While I agree some corners are rounded suggesting refinishing, it takes a fair amount of grinding to erase serials. Does anybody think that enough metal is AWOL to do that from these pictures?
It's easy to take that amt of metal off, especially using a belt grinder.
Even a coarse hand file will do it in a few strokes. Then buff it up for a nice shine!
The top of the toggles have been taken way down. Easy to see by looking at the front and rear edges of the top flat surfaces. There are steep cuts and dips coming into and out of the flat area and up into the togglepin support areas.
A lot of matrl was removed to cut off the makers logo. But it's fairly thick there anyway. Same on the rear toggle. you can see the dished out radius as the flat area climbs back out and up to the rear sight.
The front of the frame looks more rounded like it was heavily hit w/a buffer.
Proof marks are usually quite shallow. Those are placed on the finished/hardened assembled pistol. The stamps very often don't have much impression depth into the final heat treated frame and upper. So they can disappear easily in a refinish if you're not careful
The bbl's are quite soft. They mark deeply usually. This one doesn't look like it was # or proofed marked at all and then polished out. That's why I think it's a replacement bbl.
Could be a commercial aftermarket. May be a Military Arsenal made replacement.
The breech block and toggles can be extremely hard, others not too bad.
Probably the hardest I've noted are those on the Erfurt mfg Lugers. Along with the Erfurt upper unit which is also very hard.
Sometimes you can just barely cut it with a file,,sometimes not at all.
Most would be surprised how much metal can be removed from the parts of a gun in refinishing, restoration and not have it crumble like a piece of foil.
Markings, pitting, scars, dents, ect are usually removeable w/o going to welding or other filler methods.
..and then sometimes not!