I have a Colt Lightweight Commander that I sent to Metalife to have the frame hard chromed. It was not marked by them in any way.

What you are seeing may be Roman Numerals. Star used them the same way manufacturers used assembly marks, to keep the parts together. Examining Star pistols that have been field stripped often reveals Roman Numerals that have been scribed on the parts. See those three lines on the bottom of the slide rails ? Those may also be assembly marks from the factory.

Hard to make out the markings on the left side of the tang, if there is a Waffenamt it may or may not be one of the guns from Bulgaria that had spurious markings applied.