That's a nice looking revolver! Like Rikkn says, they are hard to get along with just one. Same goes for the Webleys.

The BNP/crown markings are 'Birmingham Nitro Proof' markings. Frame, barrel and every chamber on the cylinder usually. Those are commercial proofs applied when the gun was surplused but before it was allowed to be sold in the UK on the commercial market. The 'England' stamp in an export marking when the gun was most likely shipped to the US for sale in the 50's or 60's. Just denotes country of origin,,not to be confused with the import marks used today that came into use since 1986 that demand importer, country of mfg, and caliber.

The Bakelite composition grips are correct for a Mk1** revolver. The ID disc was supposed to be used to stamp unit indentification, weapon #, etc onto it, but the brittle nature of the Bakelite made most of the stampings go right onto the frame backstrap and frame itself.

Have fun! They are great shooters. There are still WW2 surplus 38 Enfield 'web gear' holsters, belts and ammo pouches around yet.