Funny that they would go to the trouble of marking them there instead of on the receiver wall.

Were there not two serial ranges? One with four digit numbers after the "C" and one with five digits and if so, did the SN range not start again at 0C00000 for the second range?

I have a 0C59-- 1942 MkI (not MkI*) here that is US PROPERTY marked, albeit rather faintly.

Any rifle made without US PROPERTY would have been paid for "cash and carry" as it was in the USAicon while the Britishicon had any cash and assets to be divested of.