BeeeUtiful rifle! I had a BSA marked No. 2 pattern in 303 for a while and then traded for an F. Beesley marked No. 1 pattern in 375 Express with the flat top engine turned rib, engraving, and extra cost tang safety, which I still have. Yours looks like a No. 1 as well.

All these BSA built sporting rifles are really beautiful. I always have wondered how much "regulating" and modifying firms like Rigby or Beesley actually did to these since they look exactly like the rifles in my 1920s BSA catalogue.

John