Follow up from last night. I checked the first Northern California Collector's Directory, compiled in '74 and released in early 1975. I found Mark Larson & Rich Sawyer listed. Also found Jerry Stone (who posted earlier). Maybe you didn't sign up as it was optional. Attached is my table confirmation postcard from the 1979 Acalanes show. Dobbins asked me to bring along a Pete Rose bat. It was probably worth about $25 in trade then
