But I doubt he ever set foot in a machine shop. Making things is an entirely different skill.
I've taken apart cars many times. I know when I'm being fed a baloney sandwich when taking my car in for service, and use that to pare down the estimate sometimes as much as 50%.
(For all the women who rightly complain about being scammed by auto mechanics, I can vouch for them doing their best to scam me about 75% of the time.)
Obviously ideas to improve the economics of space exploration can come from anywhere, but one of the first places I'd look would be the Boeing machine shop.
And we haven't touched on human spaceflight, where economy must be balanced with safety. Hmm, I wonder what industry has the most experience with such engineering tradeoffs?