Absalom,To determine whether marking is even an issue on these, we would need a specimen of an earlier .38 Colt, documented to the Pennsylvania Guard, to see if Pennsylvania had service-specific markings added.
On the earlier DA Colts, the US Army stampings, RAC and such, were applied by ordnance inspectors at the factory. These Army Specials obviously did not go through the standard ordnance inspection process, and Pennsylvania may just not have had state-specific additions. But to determine that, you would indeed need comparison examples.
we need a lot of good luck!!!