I got most of it from Flaydermans, but also from a couple of other books. The only Stevens single shot I have is a Model 10 which, of course, is a totally different gun.
When I first got into collecting, an old timer and good friend (gone now, alas) gave me a good piece of advice - every time you buy a gun, buy a book. Not necessarily a book about that gun, but a decent quality gun book. (At that time, there weren't many; we are blessed today with a tremendous number of high quality books whose price reflects the quality.) Skip the umteenth regurgitation of old stories and nonsense put out by the gunzines, and get the best you can possibly afford that arose from original research.