Good eye, Tom! There's something else: A Model 7 should have a small stamp (The newly listed e-bay 7-5 has this). It looks like Jim's stamp is the standard. Could be something to Ben's observation that the blade has been altered in some way after it left the shop. The other e-bay 3-6 you posted a photo of is a 4-6.

I'd still like to hear from Jim on the sheath numbers and the handle and blade length.

Best,

Ron