Good news. Heat from the drive home did most of the trick, and I finished it off with 0000 steel wool. I also used a green Scotch abrasive pad, but the steel wool worked better. So that's done. Now on to asking my wife to do some sewing . . .
Thanks for the very helpful comments!!
Riding my airhead is like eating chinese food . . . an hour later, I need to ride again.
1978 BMW R100S "bitza" (R80/7 frame)