Ya I agree, man I wish it was 1975 again, but then again, probably a good reason these amps are in such good condition: they were hidden away!
I think alot of people used one of these and the got huge paranoid and boxed it.
I could be wrong but I remember just 2 decades ago you would be instantly ratted for anything so I gather when that amp was made, you could get raked over the coals for running a boot.
All the town grannies would be all over you.