Yes, it looks fine to me, even if the serial is not as anticipated. The bolt bodies made by BSA have the capital letter 'B' stamped where the 'M' is on this one on production up to some point in 1943, & M47/C thereafter. A BSA bolt body would also always have the hollowed out bolt knob - can't quite see whether this one does or not.

Quite why the serial is atypical I do not know, but suspect, as as Alan alluded, that being of very early manufacture the serial ranges were not allocated/not yet religiously applied.