Printable View
Looks like a pretty standard BSA of the time. Hitting these numbers stamps seems to have been King Kong's war-work job. This one has survived post-war overhaul that has wiped out almost all the other markings.
https://www.milsurps.com/images/impo.../04/orig-1.jpg
See if the serial was lightly scribed on the side of the action body or socket, however faintly. If there's any sign of it, that was probably the number applied during manufacture. The impression marking was often done later.
Thanks for all the input.
So this could be the serialnumber given during production or at least during war time?
Looks to me like it could've started out as B7715 (a normal '42 BSA s/n), with the 'B' either overstamped or distorted somehow.