Pretty much what Marty says. A lot of are self taught, right or wrong. I have bought most of the metal shaping books by Ron Covel and others over the years. They are a great resource to set you on the right path.
I had a set of roles built from pipe . Loaned they out never to see them again . Not hard to build . Goggle is your friend for this
BTTT...great Thread @brady1929...it's got me dreaming...I've been thinking of an aluminum Hood for some time now maybe just a top...I even recently got some welding tanks...Thickness and grade of aluminum mentioned and tech to boot...you even posted a good link... ...Inspirations...the Helen and Bart Orr Roadster is cl***...