However the older solders have a much higher percentage of lead in their composition which makes whiskering less likely. I have two Zenith Z-120s made in about 1980 and thus coming up on 50 years old which don’t have any issues.

I know of a running TRS80 and a BBC Model-B, but the retro-heads who own them jst pwer them up now and then, not in constant use so as not to heat-stress them. TBH they smell a bit. My theory is the transformer windings are on the way out.

Wire-wrap avoids that altogether: https://en.wikipedia.org/wiki/Wire_wrap