Chasseur - This was Winfer's first book on single shot rifles and subsequent volumes (up to Vol 7 + 8?) include many updates

A very good book for single shots, it was the most difficult for me to get to complete my set, although I understand it may have been reprinted

I love books, especially on British Sporting Rifles and would recommend it for that, but as to your original question, it does not give you anything on his express rifles especially if you mean doubles (As I am sure you know, the "express" is the cartridge)

Looking at the book now, as I write, (type?) the introduction is on general gun and rifle manufacture, especially in Birmingham, and then goes straight into the single shots

I will happily send you excerpts you wish, but with 180 odd pages, none referring to double rifles, you would have to tell me what you want

I do not know of any detailed book on Alexander Henry except this one, perhaps Curl (and others here) could be persuaded to write one!!

TH44