My 1912 BSA is about 18000 rifles after yours, and is nowhere near as tidy. Mind you, for $150 AUD, and with all matching and original numbered parts, I'm happy.
Mine has the NSW RANR stamp on the butt as shown;
Any info on this stamp would be most welcome. It has the sold out of service marks which have been cancelled;
The pre-WW1 SMLEs are a favourite of mine. Lovely rifles there.
Cheers,
Matt