Telephone Repair Illustrated
Prior to the Internet, libraries were the first places someone could go to get some DIY information. It used to be a library card and a few repair manuals meant everyone could do basic repairs. More complex repairs went to your local electronic repair shop. I remember in the early 1980s taking an old tv to our local shop to put in a few new tubes.
You will love some of the pictures of “modern” phones, especially when it has an answering machine built in. (1980s me would have though that was the bomb!) Clearly, repairing a phone from the 1980s or 1990s isn’t a priority anymore, but some libraries would do well to hang on to some of those repair manuals.