Quoting Mr J.Goldsmith...
"Between about 1972-1982 Kosmic had a factory in O'Connor manufacturing all types of quads, bass cabs, etc...
That particular quad was made in a few different types. The budget model had Plessy-Rola 12" speakers. The standard model had e-tone 12" speakers. The real find (if anyone can get them) is a model that had Celestion Greenbacks in them.
On the back, there will be an aluminium plate. If you could quote the number, I could find out what this particular amp is."
Hope that helps!