Just got back from a jam with some people I hadn't met before, except for the host & hostess. I took my A.E. Smith Shelburne I which I bought new in August, 1980. A guy came over and asked to see the back of the banjo - it has a distinctive internal resonator. He looked surprised but pleased. He then got his banjo out of the case - a twin of mine! Weirder, mine is #503 and his is #506 - brothers. Turns out he got his from the same music store I did, and the owner ordered one for himself as well. So there are three of these in the area and I've never seen another one until today. A final bit of serendipity, the woman playing piano tuned out to be the ex-wife of the music store owner!
#506 is the better used banjo though, Brad Leftwich apparently borrowed it for a concert as he had only brought a fiddle (not sure what the venue was).