Late 91/38 cav

Hey, guys!
I just picked up a 91/38 cav carbine with a YO prefix. It's a FNA-B, with no date markings. Interestingly, it has an overstrike on the last digit of the serial number on the barrel. The receiver tang has the second (overstruck) digit, and the stock sports the other. How late did they produce these? I have seen that XO's run in 1941. The bayonet is tight, but unnumbered, as is the bolt. Crisp stock, no cartouches. Very late cobble job? What do you think?
Thanks, CFR

YO series FNA's is 1944 YQ2642 is the final serial number.

Late war they went with minimal markings.