Wm. Enders was a tradename used by both Simmons and Shapleigh Hdw., St. Louis, (Simmons also used KK and Keen Kutter), in several variants; Oak Leaf, Royal Cannon Breech & Western Royale (single barrels) and Enders Royal Service, Royal Field, Royal Western, and Special Service.
Wm. Enders Oak Leaf, Walden, N.Y. J. Stevens (likely) Model 105
Oak Leaf single barrels were also marked "Patented August 12, 1913" by J. Stevens Arms & Tool Co., Chicopee Falls, Mass.
Enders Royal was a Hunter Arms Co. Fulton
Enders Royal American, possibly by both Crescent and Hopkins & Allen
Crescent Enders Special Service
There was an Enders family in Schoharie County, New York. Walden N.Y. is in Orange Co.
In 1854 there was a Enders, Simmons & Co. wholesale clothing store in St. Louis
A Wm. Enders was in St. Louis in 1898
https://books.google.com/books?id=m3I-A ... 6-PA30&lpg
He was a principle (still sale executive?) with Simmons Hdw. in 1912
https://books.google.com/books?id=8Zw7A ... -PA142&lpg
A 1913 Wm. Enders trademark registration lists N.Y. and St. Louis
https://books.google.com/books?id=FWtZA ... =PA685&lpg
Simmons Wm. Enders Oak Leaf tools, 1913
https://books.google.com/books?id=dJs7A ... 6-PA19&lpg
In 1914 Enders was a Vice President
https://books.google.com/books?id=tpY7A ... =PA348&lpg
A trademark was registered for the name in 1919 also
https://books.google.com/books?id=eIixl ... =PA186&lpg
and a patent
https://books.google.com/books?id=CA5WA ... =PA649&lpg
Enders may have left Simmons and started his own hardware line in 1915; Wm Enders Mfg. Co. St Louis
http://www.missouricorps.com/corp/361813.html
In 1942, Mars-Enders Hardware was established in Brentwood, a St. Louis suburb