Mik,
I'm not looking for an argument here. I agree with much/most of what you say. "A safe and conscientious operator is the thing that makes it all hang together." But, since Ohio has no required boiler inspection of steam tractors, how do you protect the public when you have an unsafe and non-conscientious operator?
I think if you are going to take a tractor out in public, it needs to have been inspected by some qualified individual. It could be a state inspector, an insurance company inspector or a club inspector who has received state certification, but I think it should be required for show attendance.