Richard Flanders, you're right about the hinge screw. This came down to me through two other relatives so I can blame one of them
. There is also some wear on the outside of the trigger guard and a light rust coating on the inside - probably from fingers, which is what prompted me to ask here.
Mike Franzen, I had to look up those gun parts so if I didn't get these pictures right please direct me. I'm not ready yet to take the hinge screw out to get a better shot of the breech face!
George, I agree my flash is causing some odd reflections. In these latest pictures the barrel has a brown tint which is NOT rust (honest) just a weird reflection.
Thanks everybody again.
Sally