1937 S/42 Proof Marks Question

[lugercollector]

I recently purchased a 1937 Mauser Luger in the 5000y Suffix range....the mag matches,although it has a stick winged E63 proof mark,but the gun has droop winged E63 proof marks??....is this possible????the mags number and suffix stampings look identical to the Lugers stamps......could there have been an overlap on the proof marks??or would they all have to match up???....Thanks...