My brother found a 1960s Watkins Westminster Tremolo guitar amp abandoned at the side of the road alongside a really shoddy guitar with nasty microphone pickups sometime in the 1980s. I ended up with it - and the guitar - knocking around as a noisemaking devices for many years, as the valves in the amp were highly crackly and prone to overheating, the connections were dubious and it fed back like crazy. I loved it.
I asked a friend who repairs amps to have a look at it, which he duly did, made it work nicely and brought it back for me to try out; it sounded great, never better, with a rich warm tone and no crackles. I immediately gave it to said friend since he’s in a raw and raucous blues band and would actually use it much more than I would, which he set out to do. It sounds great these days, looks immaculate now that the furniture has been cleaned up, has gone to the right home, and I’m glad I got to pass on a piece of musical equipment to a real aficionado.
I just checked and those amps go for upwards of £400 at auction, which is nice; but as @darenager mentioned above, for me these are instruments to be played and enjoyed, not investments.
I still have the guitar somewhere, sans strings and sounding horrid, I’m sure.