One of my big regrets is not ever having seen him perform. I can't even remember him playing around here. Is that possible?
If he did, it probably wasn't for BGP. I have a spreadsheet that I got from a friend who worked for BGP in the 90s that supposedly lists every BGP-produced show from 1965 through 1989 (close to 10K records), and neither Gerry Rafferty nor Stealers' Wheel are in it. Lots of Bill Rafferty, Jerry Garcia and Ten Wheel Drive and Asleep at the Wheel, though.
I suppose he could have played the Boarding House or the GAMH back when, but I don't know of a database of their shows.
ETA: His Wikipedia bio (source of all things) refers to his "general reluctance to perform live" so that would support the theory that he didn't play the States much if at all.