Glad you are catching up
You can use odd search terms, like TM9, or SNL-G, or whatever. I've turned up a few reference works on there at the right price. I think one of my Dodge VC Parts Lists came from there, and that is as rare as you can get till you move to vehicles that didn't get past prototypes.
Just to be fair, there are also some completely insane prices on there - if you search for something with 100 results just check the range of prices - usually from giveaway to insane.
Gordon