That’s awesome! It’s super cool you have access to some living history like that, I’m more than a little jealous. I definitely agree, there’s a real sense of accomplishment to putting together a drawing by hand, it’s an art unto itself that is rarely appreciated these days IMO.

It’s great that you’re also using those drawings to actually fabricate stuff- that’s probably the fastest and most effective way to determine whether you’re communicating sufficient and appropriate information. If you missed a dimension or callout, you might not notice unless the machinist feels charitable and asks you (many places will make assumptions and keep moving, rather than hold up production) or the end product isn’t functional in a way it needs to be (e.g. parts don’t fit together, a thread is missing, etc.). It also better informs your design, as you understand how to make the thing you’re designing and know when you’ve drawn something impossible to make. I think some of the more research-focused schools miss this, as they spend so much time on theory without any practical experience to back it up, and thereby produce engineers who are entirely disconnected from the processes they oversee or contribute to.