Wade,
To start with, can you take a photo or two of the area(s)? I do understand what you need to accomplish and can envision that the vertical or angled portion of kick ups of the steel chassis are poking into the area under the seat, correct? Is this car currently being built and the body can easily be removed? Is the chassis already painted? I need to know these things first and then I can walk you through a process with no problem.
I'll take a few pictures in a day or two. I have a camera opportunity.
You are on track with what I'm referring to.
Nothing has been painted and body is still easily removable.
Thanks