Bill, you may have something other than a 728. But since your gun has the "tons" proofmarks, that certainly puts it in the 700 series era. If you're sure about the date of production, it could be that W&S produced a special series of guns for Orvis. Have you tried checking with Orvis? Does it have a serial number in the 728 range? All of those are 728xxx.

Last edited by L. Brown; 02/06/16 10:19 AM.