You're much more likely to stumble one something more modern, but that modern something is also much less repairable. It's great if it works and if it can run Linux or Dusk OS, but when it can't, you're out of luck.
With a 6502 or other such CPU, the machines you scavenge them from are much more repairable and adaptable. You can use those components like lego blocks. It breaks? either repair it or strip the working parts to use in another frankenstein computer.
I get the idea of making a frankenstein computer, I just disagree that 6502 is THE platform to do it on. Practically, there's no way for me to find it. Other comment mentions ARM, which is a much more interesting proposal to me
ARM is an interesting proposal if you want to order a SBC online and run software on it. Soldering an ARM CPU with low tech tools? That's something else.
Time of a strategic reserve of J-Links?