Proof Marks on 1933 Model 42 skeet|Winchester Shotguns|Forum|Winchester Collector

Recently purchased a nice Model 42 Skeet with English stock with a 14XX serial number.  The gun is original and in 95% condition.  I immediately noticed that the proof marks on the barrel and receiver were strong but not full, i.e., they haven’t worn off or been buffed off…they just aren’t fully stamped.  Yesterday, I had the opportunity to examine an identical Model 42 in like condition with serial number 15XX and it, too, exhibited the same phenomenon with regard to the proof stamps.  This tends to make me believe that the die used was nearly worn out.  Can anyone on the Forum substantiate this for the 1933 Model 42 in the early four digit range?