I have a no 4 mk 1 with a 'BW' stamp on the receiver dated 1944. I checked the links for which manufacturer 'BW' would be but could not find one. Also, this rifle has a magazine matching the serial # on the receiver also marked 'BW'.
Also a few curious things.... it appears to have a replacement stock and upgraded mk II sight, but the trigger is still the old Mk 1. Also the side of the receiver does not have any rebuild marks etc... Please let me know what pics you would like to see to help me identify this rifle.
But first, does anyone know who this 'BW' manufacturer is?