Circunse. would that be salt blue or rust blue or do you care, also does it have to be off a mauser. Will check stock and see what I have but 56 rings a bell.
I see your other post states that your luger is a 41 coded byf, will check for you later and see if I got a unmarked plum one. Short of that contact lugerdoc and see what he has. He is a forum member so do a search and find his email address.