When I saw this thread, it rang a bell from years ago when I read an article about this arm titled The Fallible Infallible
. It stuck with me because my Father-In-Law owned one, and I loaned him the book I had which the article was in.
I have just finished digging through my old library, and located it. It was an article in The Complete New 7th Edition of Guns Illustrated
I remember the name of an article I read thirty five years ago, and can't remember what I did with my coffee cup which I had in my hand five minutes ago!
Anyway, I sanned in the entire article so I could share the information in it with you, as it gives a lot of historical information on the gun, as well as technical information.
BUT - the size limitations on pictures here are such that the article becomes unreadible when shrunk down that much -
SO - I put it on one of my web-sites in reasonable size, only shrunk to 80% of original scan, where you all can peruse it, download the scans, etc..
You can read the five page article HERE
All the scans are on that single page which makes it BIG, so be patient while it downloads unless you have a super-fast connection.
I hope this helps -