Ron,
I see your point about the availability of resources during war time, and that would explain the different thicknesses, more to function than symmetry.
Thanks for the pictures of the transition sheaths. Interesting how the keeper goes thru the slot, then fastened by the small rivet. Perhaps the slots were to compensate for the smaller rivet? Larger rivet would hold more securely, and when they transitioned to the smaller rivet, passing the keeper thru the slot provided a bit more strength, and when combined with rivet, added up to the general strength of a larger rivet. I may be off track, but that seems to me to be what was going on.
Thanks Ron, I have learned alot this weekend about the old Hunters.