Jim; I have an H grade SN 67333 with steel bbls stamped SB&C. The stamp is deeper at the S & sort of fades out at the C, with nothing else showing. Ahead of the S a little bit is a small diamond (about same ht as the S) with nothing inside. Is yours steel or damascus?
I also have a two hook damascus G SN 20633 with about half (right side) a makers stamp. This one has an oval with a crown in top & in bottom what shows is an L. I have a reference as to what the entire mark should be & who the bbl maker was but would have to look it up.
These are the only two I have with a bbl makers stamp on them.
