Too cool, Mr. Nickel...Roth is one of my fabrication heroes, up there with Indian Larry, my Grandpap, and a dude named Melvin. The venerable Dr. Tankenstein addressed this before, but I dig Roth's trikes big time, would be cool for a pedal version with a Roth influence...maybe there are and I haven't seen it. But I digress...
I just wanted to turn you on to a book..."Ed 'Big Daddy' Roth, his Life, Times, Cars and Art" by Pat Ganahl...a really cool history on him and his stuff...if the local library can't get it, amazon has the paperback for $19...it might give you some Big Daddy zen for your build...take care