I guess these answers are all going to be personal and individual!
I started full time in 1989 (purely repair workshop, no sales) so consumer repairs were usually to stuff made in the 80's or very occasionally 70's, not including odd repairs like juke box amplifiers or valve radios brought in for sentimental reasons. We did a good trade in industrial monitor repairs by Microvitec, Philips, Barco and Conrac, and dumb terminal 'screens' from Wyse, Fujitsu and Zenith. Christmastime brought in strings of fairy lights for repair (imagine that now!!).
Spares availability was plentiful with all the familiar suppliers very much in business and manufacturers all with UK offices who could help out. Service manuals or diagrams by post or sometimes (thanks Sanyo UK) by fax.
Television magazine still carried plentiful ads for surplus parts from Sendz, Bull Electrical etc, as well as spare pcbs from discontinued tv chassis, you could buy anything from a 1kg tin of heatsink compound to a roll of guided missile wire (remember that!!??).
I'm too young to comment on the trade in the 70's and by the early 2000's it was beginning to fizzle out, so my golden time was the 1990's. Radio 1 played continuously on the workshop radio, when Stock Aitken Waterman ruled the charts and Steve Wright and Simon Mayo played the records. The boss's desk emitting the odd BANG or swear word as the lights went out and he wafted smoke away from whatever he'd blown up, us engineers sniggering quietly. The workshop (and us) reeking of tobacco smoke as we had a chain smoker in the room.
Salad days !
