As a guy who has done a bunch of engineering stuff (not really) I was wondering what kind of advanced technologies you can make with primitive tools. Or at least tools that existed before they were used in that manner OTL. For clarity, describe how it could be done.
For example how feasible would it be to have "printed" circuit boards prior to WWII? In theory there is no insurmountable problem. You could use actual print rollers to apply the proper chemicals and then apply electrodes by hand. They would obviously be far inferior to early printed circuit boards, but far better than the vacuum tube circuitry in use.
Another example would be carbon fibers. Carbon fibers are actually pretty easy to make. Using Rayone fibers and specialized overs, it would be doable, though expensive. Epoxies for the matrix material were patented in 1946 so they would be just too late to be used in WWII aircraft unless you could get creative with polyethethylene using chromium trioxide catalysts, though that wasn't discovered until the 50's. Theoretically it could be done much earlier if the catalyst was known. Then you could end up with Carbon fiber/HDPE composite aircraft.
Any other potentially schizo technologies you can think of?