I wouldn't count on any library retaining such docs indefinitely. My regional library used to have a complete set of Riders TV manuals, as well as a subscription to Sams allowing me to download any Sams manual free.
They discontinued the Sams subscription last year because the demand was insufficient to justify the expense.
A couple of months ago I went there to photocopy something from Riders and they told me they had disposed of that whole set, too. To quote the librarian, "You might be the only person who looked at that set in the last decade."
In a library, space costs money.
Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html