Proof Marks on Late Damascus Barreled Guns

[mobirdhunter]

I saw in the most recent Parker Pages Josh's list of notable serial numbers for Parker guns, one of which was a very late Damascus barreled gun with the Parker proof stamping. An implication of the listing was that not all late Parker Damascus barrels were stamped.

So, were all late Damascus barrels stamped with the proof mark? Since the factory was using remaining Damascus barrel stock, did they treat those barrels any differently in their proofing process in the mid-1920s when they were winding down using Damascus barrels?

Thanks for your thoughts.