I also have one. It turned up in a box of assorted small arms ammo which we found in my late father-in-law's garage. There was also a partially full box of .38 S&W that contained two rounds of .38 long Colt, case marked ".38 LONG." The Maynard has no markings (and no primer).
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.