Great to see this thread pop up because I had just been doing some looking around about my old stuff. I found out that just like pinball there are a bunch of people who are into all of the vintage AV stuff, and they also restore them. This includes things like replacing caps, making electronic adjustments with scopes, and so forth. And, they even argue about replacing the lamps with LEDS, just like pinball!
I have a Kenwood KA-3500 amp and matching KT-5300 tuner. I bought these in July 1976 along with some speakers, a turntable, and the ultra cool Bic FM 10 antenna box, which I think is gone but possibly might be sitting in the attic. This was a ridiculous amount of money to spend in 1976 when I had basically nothing. But now 40+ years later I have to say it is some of the best money I have ever spent. These traveled with me everywhere I went and entertained me for all that time. Sure I have a fancypants modern AV receiver in the living room, but this amp and tuner still are doing duty even today playing tunes in the garage while I work on pinballs. These are connected to some Radio Shack / Realistic Minimus-7 speakers, and it sounds great for playing FM or even playing off an iPod connected via a docking station. I also have the turntable still and use it occasionally to digitize some vinyl that can't be acquired otherwise.
Soon I am going to work on the amp and tuner and Deoxit the pots. They are pretty crackly. I will clean everything up nicely but that's probably about it. I don't think I will get into replacing the caps unless I see something strange when I take the cover off. Everything works perfectly so I don't want to mess with it.
I love all the vintage stuff, especially those old receivers from Marantz, Pioneer and others. The designs are so cool, way better-looking than what you buy today.
An indication of what a packrat I am is that I still have the original receipt. But at least I am a digital packrat nowadays. I probably kept the original boxes for 20 or 30 years, but finally tossed them.