Probably a bunch of factors at play here. So those planes were basically made by hand. I’m sure that there was some computer rendering however i doubt that any program they had back then would be compatible with what they have now. So now you have the next generation of engineers working on a old design. They were trained in reading blueprints in college and had a few tests on it but were told you’ll never use that shit just focus on CAD because it’s easier and thats were the money is. Followed up with some diversity tyrone hires its now just easier to chop up an old plane and take some measurements.