well i don't usually resurrect dead threads but i started to type out a thread and figured I'd search first and here we are. i also have a BSA Model 1923 in 33 BSA. but there's some differences with mine. the rifle shown above is typical of the few examples of the few examples i can find on the internet. and there is very little info to be found. Mine is the only one that still has a military dogleg bolt handle. i initially thought it was a replacement bolt. but upon disassembly of the gun, i found the serial # 15 stamped on the safety, bolt, bolt release, barrel receiver, trigger, trigger guard and recoil lug in the stock. this to me indicates that is all original. now the thread id started to type out tonight was to enquire if anyone knew what would fit my receiver for scope mounts as they are missing on mine. the front is a standard Weaver 35, just like a 700, the rear is...something else. I'll post a picture below. mine also has a 4 leaf express sight , every other one I've encountered has a 2 leaf sight. my bolt body is polished in the white, all butter knife handles models are blued. the stock on mine is a very light colour comparatively. it had a dried up pad on it which i had replaced and makes for a very long LOP but at 6 ' 4 i don't mind that. going back to the serial number, most ive found online have no visible numbers anywhere, mine it clear on the safety lever bolt root and underside of the bolt release, but barrel and reciever and under the wood. mines been drilled and inletted for some kind of side mount but know way of knowing if thats factory or not.