There is a JND letter for sale here;

https://specs-fine-books.myshopify.com/collections/present-catalogue/products/1862-john-nelson-darby-rare-letter-by-father-of-premillennialism-before-leaving-for-united-states?fbclid=IwAR2ZlyA39QFv4qTQBDCYOX7Bt8o1_TPvIqXDd4RGWQ1qWVd1izuu6PcnmxY

The letter is fully displayed on the linked site, so if anyone fancies transcribing it, that would be useful.

I think they will be lucky to get $650 for it, but would be glad if they did as I'd let mine go for that type of price!