BSA....very cool project. I had an action just like that one. Originally a .300 H&H that somebody had punched out to Weatherby and ringed the barrel a couple inches from the muzzle. It was in a home made Weatherby style stock...truly hideous. The very best thing about it was the price, $275.00 in 1976. I traded the stock off for something and traded the tube off for something else and the action made several moves in our gypsy years. Finally in '87 I had a guy put it together.....Brown fiberglass stock and Lilja tube in .338 Win Mag. The only other rifle I had at the time was a 10.5 lb. '06, but only one scope between them. I used my .338 exclusively for 10 years and owned it for 20. It was inspired by reading lots of Keith, Hagel, and Bob Bell. Bell had 2 .338 rifles. His 2nd was on a pre '64 model 70, stainless tube, and glass stock. Black spray paint to take the shine off the barrel.
Yours is much nicer and more sophisticated. Can't wait to see the finished product!
