Ron,
Good thread, dude! The "1962" theory could very well hold true with Burnie's knife. The "first one in...last one out" snap theory as well. Also: Folks need to realize that it was not at all uncommon in the 60's (or earlier...or later) for a customer to "request" certain spacers, sheaths, snaps, etc. be supplied, if possible, on a special ordered knife.
These "split-loop" sheaths have a pretty decent window of time. Anyway ya' swing it, it's a nice vintage piece...and how about the "shape" of that name plate?
Best, Capt. Chris