Maybe a good close-up of the left side just behind the barrel where the numbers are supposed to be?
dju

Decent enough quality pics here, Dennis!

more pictures
 

No signs of any proofs or numbers being removed. No dipped in, dished out places on the metal. Barrel is proofed "E/623", never serial numbered. Don't have a clue what a "hump" is. ( I do, but I think it does not apply in this situation) No suffix. Reading in the big red bible, it's a variation #10. Put together from parts late in the war. So, that being taken into account would explain it. Ifs it is an attempt to make a Banner Luger, why make a $2000. one, when they could have made it into a $5000. one? Anyway, I,m getting the hang of taking better pictures.

Well I've never seen the serial number placed on the right side of the receiver AND in such an unprofessional manner.
But I'm stumped here. It does appear to have been built but never numbered.
I'd really like to hear from some others as to their thoughts and speculations.
The pictures are getting better. Take some more like the last one, close-ups, of different parts on the gun.
dju

The barrel was made by Steyr.

Steve:
Care to elaborate a bit?
How can you tell the mfg. of the barrel, and more importantly, when was Steyr making Luger barrels; pre-war, war-time, or post war? Were they a common supplier?
This may help us in establishing a lineage on the gun. Maybe.
Thanks.
dju

Steyr used the E/623 acceptance stamp. These barrels were used as armourer replacements during WW2. I suppose there were probably quite a few manufactured. You also find Radom's with this acceptance stamp as well.

I think the subject Luger is a parts gun. Of course that's only my opinion.