I used to work in configuration management. Among other things we dealt with the preparation, duplication, submittal of the various drawings, etc., that went into the technical data package of our products. It was never really submitted as a separate and complete discrete package but was sent in running submittals as the products were developed and put into production although I suppose we could have taken that filing cabinet full of fiche cards (also mentioned above) and copied every single one of them at great expense. That was years back and before things became so heavily digital as we have them now. A rifle would be relatively simple compared to a more modern electronic product of any complexity.
I'm going to guess that even back during the time the M14 was developed and in production, the contractors and subcontractors probably didn't get a real, complete, technical data package. Many of them probably already had significant portions of it already on hand or would get the specific documents needed. For example, MIL-STD-105 (mentioned above) was a standard that provided procedures and tables for sampling by attributes for quality purposes. As in, when in production, for a certain gross quantity, how many individual pieces would be picked and inspected fully. So your typical contractor already had it and was familiar with the requirements. Likely there are also embedded documents which tell how piece parts are preserved, wrapped, packaged, etc. And the standards, specifications for the preservatives, the wrapping, the boxes, the marking, and all of that.
It's a massive amount of detailed drawings and related documents treeing down through all of the parts and back to the raw materials. Paint used to mark the sights? Types of steel used in parts? The stock? Specs for the wood, inspection details, shape, size, weight disqualifying characteristics, finish method, specs for the "finish." Or for the fiberglass, all of the materials, the manufacturing process, the painting process.
Oh, and just for fun. It's all old. I'd bet many of the documents have been superceded although theoretically a later version of a standard should not conflict with earlier versions.
I'd suggest sticking to the top level documents and then deciding if you really want to pursue going for the whole thing or just getting some of the drawings.