solid state power amps, golden oldies

A consideration on older amps might be speaker connections. They might have those old, "useless" spring clips that will not accept bananas or heavy speaker wires. You will also find many with 'captive' power cords, eliminating your choice of upgrade cords.

That said, there are many bargains to be had. Look at Harman/Kardon Citation series, Hafler, Carver, SAE, G.A.S. All were nice companies in their day.

I particularly love the older McIntosh gear for both sound and collector joy.

Nikko amps,
AudioResearch D100,
Nakamichi PA100...

Threshold S/series and the Forte Model #4 would be at your cutoff point

One amp manufacturer is not here - B&K Components - they made great amps during this time period. The ST-140 was probably their biggest seller and was rated as one of the ten best buys in Audio according to HiFi Heretic magazine. I had one and also the EX-442 but I had the Sonata version which came out in 91 I believe. That was a great sounding amp, but there are many others too. Aragon, Forte, Sonographe, Superphon are all great too

I'm not so sure the oldies were "golden".
especially when you hear a high quality tube amp of recent yrs.
Could never go back to ss after i know a good tube.
btw I bought a used Marantz 250 last summer, was going to use it for bass supply on dual amping.
gawd aweful super duper grainy sound. Can't believe I use to love that sound in 1970's. YUCKKK