I'm looking at this ART II scope and mount that is coming out of a large Virginia collection. It looks original minus a missing magnification ring spindle and a reticle sans the 30 MOA left and right Mil dots. What can the experts tell me about a S/N 5384 and the mount is hand stamped "0350"? It looks like it has the standard 300-900m cam but I'm still learning and taking notes from a buddy who carried one in 2nd Bat. The package is priced well under $1000, is tight with clear optics and looks real to me. The seller also states it was a USMC piece, any characteristics to back up that claim?