I know for sure that we went to Casa de Pico in the 80's but I do remember that Casa de Bandini was next door. Was Casa Del Reyes there too? Or is it there now? I think that I also went to another place down there a time or two that may have been called Casa Guadalajara but I'm honestly not sure. We don't go to Old Town unless someone is in town and wants to check it out so it's been awhile.
I had to do some searching, and in that searching, I found that plaza del reyes was only contracted to its current operator in 2009, and I think was renamed that and it's restaurant renamed casa del reyes after this new contract.
I was at Camp Pendleton in the 1980s. Any time I went to San Diego, the old town exit was either the same as or close to the exit for boot camp, so that wasn't an area that interested me.