You might think so, but for the most part, you could have the complete set of shop manuals for an A-10 and they would show you that part no 345-2299108-rev 03 goes over here and is held in by 8 screws of type-—whatever.
But there is no place where you can go to get the manufacturing details of that 345—— part; you don’t know how long x wide x high it is...beyond your ability to measure it which obviously could be done and accurately so. That information is gone. The shop manual for your 1963 Ford doesn’t show you how to make a distributor, nor the points.
But even more removed is the tooling, the dies and fixtures required to make hundreds of that part all identical, precisely so it can exist in a sealed package labeled 345-xxxx and available to the mechanic who does not need to manufacture it and does not want to and probably does not have the tools to machine said part where his job is to fix airplanes. We know for sure that stuff is long gone.
All this is not to say that these parts could not be laser scanned by some whiz-bang machine and reproduced via 3D printing or other means. That would be a pretty pricey project, but probably 1/500th as costly as developing a new plane from scratch.
“.... but probably 1/500th as costly as developing a new plane from scratch.”
Well, not exactly from scratch since you have the actual planes to look at and all the parts to look at, and all the plans, diagrams, schematics, and on and on, to help you.
Then just add all the latest tech and VOILA! SUCCESS!