No CAD drawings here or solid modeling programs, just some graph paper, pencil, and an HP-15C calculator. I'm a metallurgical engineer by profession - not sure if that helps or hurts, but I like to think that I have a decent understanding of how metals behave. Holo-Krome bolts are probably not as good as some aero-space stuff, but I have ready access to these, and don't have ready access to aero stuff. I feel pretty good about this "build", and hearing that other racers think the cage looks good instills more confidence.
The eight grade 8 fasteners holding the seat in place should do a fine job - that's my personal opinion, and would be my professional opinion as well.
Thank you very much for the kind words, Rex. Don't be fooled by the pics, plenty of parts get modified or finalized in my garage. I spend a lot of time sweeping up grinding grit and making sure that no metal shavings get tracked into the house. As they say - if Mama ain't happy, nobody's happy.
My wife is very supportive of my hobby - I'm a lucky man.
Steve.