Drew, thanks for the response, super helpful. I don't think I have any direct relatives in MO, but on the other hand there aren't that many Breitenbachs.
Are all SxS firing pins that way? I was thinking my Merkel was different, but am probably wrong. I did know it was a 2.5 chambered gun and have been reading the pros and cons of shooting 2.5 shells, lengthening chambers, or shooting low pressure 2.75s. My plan for now is to just stick with 2.5 RSTs. I figure that is the safest bet.
On another note-does anyone know of a smith specializing in older sxs in MN or the Midwest? I might as well send it off for a check and cleaning.