Although this does not answer your specific question; this can help:
FAQ:
http://forum.lugerforum.com/showthread.php?t=13121
An unmarked is either a DWM (many were unmarked, and when you say unmarked, that means no "acceptance" marking, its not a proof as some of us accidently say sometimes {you proof parts that take stress, these kind of parts are "accepted"}); or a Mauser non-military sometimes is not accetpance marked.
Ed