Mark,
Yes Bill and Nacho were partners (and brothers in law...Bill's wife Connie was Nacho's sister). Bill owned San Diego Sports Collectibles on 5th Avenue downtown (about a block or two from Balboa Park). I actually worked for him there for a time, while going to junior college.
I never attended any of the Hara/Grauer shows, as I left San Diego in January of 1985 to join the Air Force, where I spent the next 24 years of my life
. I do remember Gregg, as he set up at shows, but didn't begin running his own shows until after I'd enlisted. The only shows we had prior to that were monthly shows at the old Parkway Bowl in El Cajon. That's where I met Steve Brunner, Tony Galovich and a few others from the L.A. area. There were also a couple of big annual conventions called "The San Diego Show" held down at the Town and Country Convention Center. I saw and bought my first 19th Century cards (N28 Clarkson and Keefe) from Larry Shane at one of them. He'd come out from Philadelphia for the show. I also went to a couple of shows up in Anaheim.
Back to Bill Goepner, one interesting anecdote...his father was in the Navy in 1941, and was the man who fired the U.S.' first shot of WWII, on the Japanese midget submarine that was caught entering Pearl Harbor prior to the Japanese fleet's arrival.
Steve