Michael, $850 for a parts Artillery isn't bad,
Sounds like a fun gun, both of them actually.
The Unit Mark; L.Me.276 I would say is actually a Police Marking, which would stand for Landjagarei (rural constalbury) Merseburg (weapon) # 276
The frame is obviously from a Police Era gun with the marking and safety. Does it have a sear safety? I assume when you said cut safety that was a magazine safety.
Ed