It was, actually. The machinists at Boeing 70 years ago were taught their craft. They didn't just figure it all out from scratch; some aspects of aeronautics were novel but shipbuilders were making propellers before William Boeing was even born.
> They built it then and it can definitely be built again.
I can't see why I should trust this line of reasoning. I baked a cake yesterday, so I should definitely be able to bake a cake today, right? But I ran out of flour and stores are closed.
Not to say that it can't be done, but in today's economy, with today's culture, it just isn't a sure thing.
This is absolutely incorrect. Most of the materials machining advancements to make light aircraft parts had to be done specifically for aircraft. Ship building is completely different and largely irrelevant.
> I can't see why I should trust this line of reasoning.
Because this wasn’t some long line of training from centuries of wizardry. Materials science was a joke 100 years ago. We can do what they did then to learn manufacturing but we can do it significantly faster because we have simulations and chemistry knowledge that wasn’t lost.