Going to gently disagree, gnoahh.. it's known that they bought a bunch of 720's for training purposes, and some "riot" versions with shorter barrels for security personnel.
While some of these very possibly later became "loaners", I doubt the Army would have acquired any number of 720's after the war - especially since the plain receivers weren't being made after the war.
Army even has a TM for the 720. They definitely didn't do that for loaners.
http://www.cgsc.edu/carl/wwiitms/TM9_285_1942.pdfIf the markings are much different, a guy needs to be careful. There have been a number of 720's that are counterfeit military rifles - stamped faked or parts switched.