Don't forget about the training films!
You're contemplating a huge undertaking, although you're a smart fella, ALL of the manuals are likely to be too many for one person to attain, organize and make freely available.
You might consider some limitations, such as manuals printed after 1959, related to machines-engines-vehicles-metalworking (not personal hygiene, how to dig a latrine, rig a tent, for example).
There are various levels of manuals for almost every piece of hardware used in military service, from operating manuals actually used by various personnel in daily operations, to overhaul literature used only at specialized repair facilities. So, the information in some manuals may have been written/compiled by the gubmint, printed by the U.S. Gov Printing Office, but other manuals may be the works of various equipment manufacturers.
Then there could be a problem with supplements which correct errors in the the previously issued manual. There may be a database of such supplements, but probably not easy to find. Sure, you'll be presenting the manuals As-Is, use at your own risk.. but some of the info will likely be inaccurate.
If you should stumble upon a large number of paper manuals, are you going to be willing to properly scan them so they're not crooked, distorted blurry, etc? This might mean removing the spine so the pages will lay flat on a scanner bed (and keeping them in order without the spine).
All of the scanned manuals that I've seen have been done by opening the book to lay it across the scanner glass. This will work OK for something the thickness of a magazine, but with thicker manuals, this results in dark shaded areas and distorted print near the spine. Then there's the issue of the scanner reproducing artifacts of the opposite side of the page (thru the paper, like a double exposure) superimposed over the page's image.