Dad's Sterlingworth
Dad inherited, and passed along to me, a sterlingworth made in 1927. It is a 12 ga, 30" f&M gun that has seen a lot of use but still shoots birds when I take it out to open the season. Stock has been refinished and has a little more drop than most modern stocks, but it still sports the old splinter forend and can still knock the roosters down. Never needed repair that I know of, and killed thousands of pheasants and ducks in the 30s.
I would imagine there are quite a few books about the American classic doubles. The only one I'm familiar with has the production dates by serial number for the A H Fox guns. It was written by RW Lightner in 1976, and he does give the name of a fellow who would research individual guns at one time. Roe S Clark, Main Road, Granville, MA 01034 was the contact. Catalog reprints were available for $1.50 back in '76, and it is noted that R & A Moulton of Turlock CA were interested in buying A-G grade Foxes.
Good luck in your quest. The Sterlingworth was made to be used, and they are up to the task. No damascus barrels, all coil springs--easy to see that the machinist known as Ansley H Fox designed and manufactured a high quality product. Good serviceable shooters should be out there for 600-900.