I'm thinking of buying a pair of "Super Reds" but the WAF is kicking in. I believe these to be the speakers out of Momma Jo's studio that was in North Hollywood (now Dave's Room). Momma Jo's was built by Freddie Piro and the most famous group out of Momma Jo's was Ambrosia. If you listen to Ambrosia, they have a fantastic sound! I played Ambrosia for Zilch (he had never heard of them) and he fell in love with them.
We recorded there ~1974, and these are a dead ringer for what I remember was in the studio back then. The cabinets are unfinished black boxes that were soffet mounted, and that's how I remember them. The ad says they are now in Burbank and came from a local studio. And Super Reds are super rare.
https://en.wikipedia.org/wiki/Ambrosia_(band)