Took over T.H. Gregg's publishing business, at 24 Warrick Lane around 1856/7. Later moved to 20 Paternoster Square, which was also listed under many other names, such as "London Gospel Tract Depot", "Gospel Book Depot", etc. Later also 114 Camberwell Road.

See George Morrish

Open Brethren publishers which published periodicals such as "The Believer's Pathway", and "The Northern Witness".

In the Commercial Gazette for 1881  we have listed "Turner George & Co., publishers and booksellers, 40 Sauchiehall-street, Glasgow; June 30. Debts by John R. Caldwell, who continues at 40 Sauchiehall-street as The Publishing Office. George Turner will carry on business at 249 Argyle-street, Glasgow, as George Turner & Co."

In an 1884 Post Office Directory it is listed as "The Publishing Office, publishers, booksellers, printers, and bookbinders; Wm. Kyle, manager."

Also used the address heading, Office of "Herald of Salvation".

Operated from 21 Paternoster Row in the 1870s, and 14 Paternoster Row, London by the early 1880s.
Absorbed by Pickering & Inglis  in 1919.

See Alfred Holness

A fair amount of information can be found about this in Neil Dickson's "The History of the Open Brethren in Scotland 1838-1999". Here are just a few of the most relevant quotes, but much more can be found by searching for 'Pickering' withn it.

"In 1876 Donald Ross opened the Publishing Office in Sauchiehall Street, Glasgow, and when Henry Pickering (its manager from 1886) formed a partnership in 1893 with printer William Inglis (died 1906), it combined both men's names in its title." p182

"In addition [J.R.] Caldwell may have had a crucial role in the development of Pickering & Inglis for in 1886 The Publishing Office shared premises with Caldwell's firm (Dempster, 'Brethren publishing', p. 70) and JB Watson stated that it was Caldwell who invited Pickering to take up the appointment of bookshop manager (Watson, 'Pickering'). These evidences of control suggest that Caldwell may have also supported the publishers financially during this period. " p183

"It was the restricted views which were winning over significant individuals. Ritchie issued Banks' pamphlet, as did Henry Pickering, then
running a small printer's business in Newcastle. Hopkins' pamphlet was issued by the Publishing Office in Glasgow and Banks, took over
control of this concern in 1886; it was he who appointed Pickering as his manager. JR Caldwell, who was Boswell's brother-in-law, was also won over to these views .. " p203

"In 1919 Pickering & Inglis absorbed Brethren publishers RL Allan of Glasgow, Alfred Holness of London, and Yapp and Hawkins of London. It became a limited company in 1937: 'John Hawthorn', W, 67 (1937), p. 47."  p196

"In 1908 on the death of William Inglis, he (John Gray) became a partner in Pickering & Inglis and he removed to Glasgow, taking the main responsibility for printing and publishing after Henry Pickering retired to London in 1922" p354

From https://eddieolliffe.wordpress.com/tag/pickering-and-inglis/ -

"In 1906, the firm expanded by printing in Glasgow and later Cardiff and opening shops in Glasgow, London, Edinburgh, Newcastle, Dublin, Bournemouth (Keith Jones is ex-P&I), Manchester and maybe some others.  They were a chain before such were known but tended to operate independently. That was their inherent weakness. 

By the 1930s they, along with Marshall Morgan & Scott, were the two leading UK independent publishing businesses. The bookshops were a good outlet for P & I books and their printing output gave them an advantage over MM&S. 

When the new centrally-run, charity-based SU and CLC shops came along, P & I found it difficult to compete and the shops closed one by one. The last to close were Manchester in 1966 and London in 1985. However the large Glasgow shop continued flourish and survived a company merger with competitors MM&S in 1981.

The Glasgow shop was bought by STL in 1999 and became Wesley Owen’s flagship store for ten years before being bought by Koorong in 2009."

In 1981 P&I merged with Marshall Morgan and Scott (a London-based predominantly Baptist publishing house, which had acquired a number of publishing companies over the years, such as Bagsters and Oliphants) to become Marshall Pickering. Marshall Pickering was itself acquired by Zondervan in 1983 and merged into it in 2001.

John Ritchie began his business in Kilmarnock in 1880, commencing his first magazine, The Young Watchman, in 1883.

See John Ritchie

From https://bibletruthpublishers.com/about-us/c812

In 1885, Mr. John T. Armet and his wife rented a corner of a brother’s stationery store where they began what they called Bible Truth Depot. May 7, 1899, was the date of the first issue of a new Sunday school paper called “Messages of Love” begun by the Armets. It began, “Our Dear Little Friends: If the Lord permit, we hope to have a paper like this one for you every week, telling you of God’s love to this world of sinners. What could be more wonderful to tell you about than the love of God, and that love being towards us when we had no love for Him.” By God’s good hand, that paper presenting God’s love and salvation has been continuously published from that day to this. In January of 1915 the Armets began a full-fledged bookstore at 1112 Taylor Street, St. Louis, Missouri, to distribute, as the name suggests, Bible truth through periodicals, books, pamphlets, hymnbooks, tracts, and (more important than all the rest) the Word of God.

By 1947, brother Armet had been with the Lord for over twenty years and sister Armet was ready to pass the work on to others. A non-profit corporation was formed and given the name Bible Truth Publishers, with the purpose of carrying on the good work that the Armets had begun under the name of Bible Truth Depot and to add to the scope of the work by also becoming a publisher of the works of sound Bible teachers, stories illustrating Bible truth, and the biographies of those whose faith we are to imitate. In 1951 the work was moved to Oak Park, Illinois, and, in 1977, to Addison, Illinois.

Now called Bible Truth Publishers, and assoicated with the TWs. I don't know if Bible Truth Depot was assoicated with TWs from the beginning of the division, or that happened later?

"About 1809 he commenced business for himself, on a somewhat limited scale, as a bookseller in Castle Street.

When his reputation as a publisher of religious books was thoroughly established, and his profits were considerable, he succeeded in buying the 60 Munificent Liberalities premises in Berners Street, where the business has been carried on for nearly fifty years." (1867)

See James Nisbet

Nisbet publishers officially lasted up until 2008; (see https://www.thebookseller.com/news/nisbet-sold-rival-publisher)

Cambridge-based academic and theological publisher James Clarke & Co has bought the publishing assets of rival James Nisbet for an undisclosed sum. Adrian Brink, m.d. of James Clarke, said he is intending to reprint a number of theological titles from Nisbet's list under the James Clarke imprint. Nisbet was founded in the 19th century and originally published the Janet and John series of children's books. However, it has not been actively publishing for some time. "It's a useful acquisition for us because their range of theological titles has scope for success," said Brink. He added that James Clarke was planning to expand the theological side of its business by adding to its editorial team. James Clarke releases around 20 titles per year but Brink said that will increase within the next 18 months.

Began in 1891 at 51 Paternoster Row, don't know if lasted beyond the untimely death of W.G.W. in 1914. Moved to 17 Paternoster Row in 1896 after buying business of J.E. Hawkins & Co.

See comments, and also Walter Gidley Wheeler

Began in Goodmayes, Essex in the 1920s, then moved not long after to "The Ambassador Office", Barkingside.

See pictures in Comments, and also George Frederick Vallance.

Operated from 32 Water Lane, Ilford, Essex.

Seems to be on similar lines to G.F. Vallance. Published W.H. Knox. He also published "Spiritual Songs" (see back of Colossians by Knox).

Anyone know anything else?

See also William Yapp

In 1860 a congregation of Plymouth Brethren meeting in Orchard Street moved to No. 71, in conjunction with the transfer of the religious book and tract publisher William Yapp from New Cavendish Street to No. 70. Yapp, an early member of the Brethren, invented the floppy oversize cover known as a yapp binding, originally for pocket bibles. The Welbeck Street Assembly was not without social standing, its members including the 8th Earl of Cavan and the missionary 3rd Baron Radstock. ‘Welbeck Hall’, perhaps adapted from old manufacturing premises at the rear, continued in use for Brethren services and missionary meetings until 1909, when it was absorbed into the premises of J. R. Collett & Co., ball-gown makers at No. 72, the Brethren meeting subsequently in Great Portland Street.

https://www.ucl.ac.uk/bartlett/architecture/sites/bartlett/files/chapter14_welbeck_street.pdf

Begun by Paul and Timothy Loizeaux in 1886(?). First called Bible Truth Depot. First 84 years in New York (see L.o.I. article in comments) before moving to Neptune, New Jersey.

Operated from Pentonville district of Islington;

See

https://www.brethrenarchive.org/people/edward-ezekiel-crocker/

and

https://www.brethrenarchive.org/people/george-cooper/