[mrerick]

Hi Andy, and welcome to the forum.

Congratulations on your Luger.

I can't tell what is causing it, but from your pictures the finish does not look like the appearance of an original finish. It's more like a dipped finish with minimal polishing afterward (perhaps to retain the pistol's sharp edges). The lack of paint in the safety lettering would tend to reinforce that it has been refinished.

This, and the re-chambering would eliminate it from collecter interest in the USA, but this varies with each geography.

This finish appearance might also be caused by the lighting of the photos, or perhaps a coating of lubricant or grease.

The unmarked S/42 magazine is an armorer's replacement magazine.

The "10717" stamped under the trigger plate is unusual, and perhaps was done during refurbishment to your Italian legal 9x21 caliber.