Thanx all... for trying. Going to read Joe's explanation helped some... I guess that after the sheath making was brought in house (1969) all semblance of order in that department went out the window. None of my 8 sheaths are as Joe described the Atchison sheaths. But they are all varied:
Two 103s, 2-line and 3-line, both flap sheaths with 1-Buck snaps, but one has dimple rivet, one has rounded nail-head rivet.
The two wrap-around 119 sheaths have a regular rivet, but one has the 3-Buck snap, one has 1-Buck snap.
The flap 119 has the nail-head rivet and 1-Buck snap.
The 124 (3-line) is in a wrap-around with a single regular rivet for a swinging type belt loop, 1-Buck snap, but no model # stamped anywhere....
The stray 120 sheath (no knife) is like the 124 sheath, but is stamped "120."
Another 1-line small Buck is a 102 I think, but its flap sheath with 1-Buck snap and nail-head rivet is not marked with a model number. Since the knife is a 1-line, it's not marked either.... From the size and pictures, though, I'm pretty sure it's the 102....
Bottom line: Fixed blade sheaths are at best inconsistent, and I think, even mixed over time!
Thanx, again,
NA