A lot of the more 70's advanced studios were outfitted as Westlake studios by Tom Hidley who made it his Company calling card . And they were certainly quad equipped as well as being advanced with the latest in gear.
Tom Hidley's design studios became bragging rights, from what I've read.
Tom Hidley eventually moved to Switzerland I think, in 76 or 77 , where he started a new Company for Studio Equipment, known as Eastlake Studios primarily for the European studios.
So a lot of these studios in the US , boasted that they were Westlake Outfitted.
Additionally in Europe some studios boasted they were Eastlake equipped.
If you read through Billboard's "Studio Tracks" ,
in mid 70's ,section you can't help but reading this ,time and again. "This is a Westlake Studio".,or such and such is now a "Westlake Audio Studio". And fwiw all the known unsung hero quad engineers names keep popping up in that section ,unfortunately no mention of any specific quad mixing by the time 76 rolls around.