Well, got the CD today with the 4 manuals on it in PDF format.
1962_GMC_MAINTENANCE_MANUAL_MODELS_1000-5000.pdf
1963_GMC_MAINTENANCE_MANUAL_SUPPLEMENT_P-PB1000-2500_MIDELS.pdf
1963_GMC_TRUCKS_SUPPLEMENT_TO_MAINTENANCE_MANUAL_MODELS_1000_THRU_5000.pdf
1964_GMC_MAINTENANCE_MANUAL_SUPPLEMENT_MODELS_1000-5000.pdf
Seems to be pretty good quality, I am sure they'll be put to good use. The only thing is that it contains all engines and has several supplements. If I find the time, I may try to put together just the pages for my truck into one PDF so I don't have to do quite as much searching across the manuals.
For $30 + shipping, I think it was well worth it.