This March 1971 letter was found folded in a December 1971 issue of the Journal of the Historical Firearm Collectors Society of South Africa, alongside an article on John Adams' Revolvers. It's likely it was included with the journal when posted to society members. The author, William Chamberlain is seeking detailed information on revolvers owned by other collectors. The result of this survey contributed to the Chamberlain & Taylerson's book Adams' Revolvers in 1976. This important book remains the standard reference for Adams' revolvers today. The letter is printed using an old gestetner spirit duplicator and although faded it's still easily readable. 

Copyright remains with W.H.J Chamberlain.