Dennis,

I'm certainly no expert at dating RMKs, but the sheath (assuming it is original to the knife) looks to me like a Johnny Johnson loose stitch rough back, which would date it to about 1986-1991. If you want to read more about the different Johnson sheath stitchings, and dates of usage, there is an excellent discussion, with photos, on page 82 of the 'This Old Randall" thread.

It appears that the first RMK catalog in which the Model 10-3 appeared was the 29th edition, issued in 1992 (it was not listed in the 28th edition, issued in 1988). Unfortunately, it is not pictured. It's possible that the 10-3 was available earlier as a non-catalog, custom or special order?

I don't know when RMK switched from single handle pins in the 10-3s to double pins. That would give us a pretty firm 'made before' date. Maybe Joe or Mitchell or one of the Model 10 specialists can help with that.

Best guess as to vintage...1991-1992).

I hope this helps.

Bob