I compulsively collected service manuals -- especially for the Sony products I
owned -- and, as you've seen, that collecting came in handy just yesterday.

When I was a kid, the Enoch Pratt Free Library * had volumes of the Rider
service manuals, which I sometimes pored over.

I would be cautious about destroying them. You'd probably be better off boxing
them, and putting the boxes in a safe, dry place until you find someone who'll
give them a good home.

* For those who aren't Baltimorons... The Pratt library was endowed by a
wealthy merchant. It was (and probably still is) considered one of the world's
great public libraries. It was the first place to go when I had to do research
for high school papers.

https://en.wikipedia.org/wiki/Enoch_Pratt_Free_Library