A big thank you to you Crazy Horse! It's been so long since I posted this I forgot that I did. I never did get an answer until now. I'm new to metal working and this really helps. Flexing is my problem.
My first attemp resulted in the seat pan pushing the back fender onto the tire and a 100% lock up at a good speed. The little tabs for the wires under the fender caught up on the tread of the tire and locked it up solid. I never knew I could swivel my hips like that but I didn't go down. I was running WFO at the time so that was a good thing.
I've been watching some YouTube vides on making fiberglass pans but I'm new to that too. I may wind up with the only wooden seat in town. I'm a retired carpenter. lol.
I can't use a conventional bike seat because in my attemp to gat a bobber look for it, I lopped off the top of the seat post on the frame to lower it. You can cut it off but you can't cut it on. Big mistake.