I also buy quite a few manuals off of E-bay. One guy did try to slip me a re-print but I raised so much cane that I did get my money back. (The guy claimed he didn't know it was a re-print.)
As for getting manuals from the makers of the equipment I have not had much luck with Case-IH. Or should I say New Holland-Case-IH. I'm not sure but I think copyrights are only good for 50 years on printed material. My law dog is checking that out now. If that is the case I have some plans for the ones in my collection.
My 2 bits worth,