They weren't in use that entire time though and I'm guessing they were kept somewhat climate controlled too which helps a ton unlike other vintage electronics that get shoved in attics/garages and exposed to wide temperature ranges year after year. First thing I do when I buy a new vintage computer or computer accessory (I'm an 8-bit Atari guy) is change the caps (period) and then remove anything socketed and clean the leads.

You actually worked on restoring them? Do public images of the innards exist anywhere from that? I'd love to see that, the innards of old electronics and machines are just so beautiful in their simplicity. You can look at them and actually understand what is going on.

Edit: found your blog, getting lost in the images.