^scha!
BNP(Birmingham Nitro Proof) indicates 1955 or later entering commerce. .767 is the length of a .38 S&W case. A Special proofed in Birmingham would be stamped .38 Special, in London it would be .38"1.15" 4 Tons.

.38-200 later .380 MkII refers to the British service load which has the case dimensions but greater bullet weight, originally 200 grains; later 175 grains with a .360/.361 diameter. Not the old U.S. .38 S&W.

Duplicating the .38-200 is a handloading proposition.