Let us consider the following guns:

A) 1900 Stephen Grant Side-lock ejector original barrels measuring within 5 thou' of original proof marks and a minimum of 25 thou in the walls.

B) 1900 Stephen Grant Side-lock ejector with invisibly sleeved barrels.

C) 1900 Stephen Grant Side-lock ejector with original barrels, down to 18 thou' at thinnest and still 3 thou in proof.

D) 1900 Stephen Grant Side-lock ejector with original barrels, out of proof due to enlarged bores but still with 22 thou in the walls.

If A is worth 15,000, then B is worth 7,000, C is worth 3,500 and D is worth 1,500.