Nice find!
As for the Quad II part of it...
Quad II is a classic product, and one that serious audiophile types interested in vintage equipment would like. The design actually predates the Quad ESL speakers, but, that said, I think that combination would have been a standard combination for many years. I'm sure Quad would have suggested it (LOL), although I'm sure they didn't mind selling their amps to someone using some other brand of speaker.
Quad is said to have stood for Quality Unit Amplifier Domestic.
There should also be a preamp of some sort in that cabinet (the Quad II was a power amp only).
I remember when I first started reading the British audio press (in 1989 or 1990?) that Quad was a name I suddenly started seeing a lot. I don't think I'd ever heard of them before, but there were plenty of references in the British press. They were not the cutting edge company that got heavily reviewed, but a lot of those magazine readers owned Quad equipment, and there were plenty of ads for places that would service Quad.
[this post was last edited: 9/29/2018-04:42]