Yes, that's a possibility.

The majority of 40's metal snap sheaths were "left hand". There are several hypothesis for this (1) The LH sheath was to be worn on the right side because Bo believed that the initial knife thrust should a back handed slashing motion and (2) The LH sheath was to be worn on the left side to allow a 45 to be worn on the right side. (Joe may be able to expand on this). The sheaths changed from LH to RH when the metal snaps transitioned to translucent. In the case of your second knife, the snaps had not completely transitioned.