When I came to the Huckleberry RR in 1990 we operated under the State of Michigan Boiler Div. rules. About 1994 or so the FRA in it's infinite wisdom decided that, since we have a public grade crossing, they will inspect our steam locomotives. Since that time we have maintained dual certification - complying with FRA regs, but keeping the State paperwork up to date as well. There is a slight additional expense but will make the transition back painless if the FRA decides not to inspect us anymore. Any repairs must be done by someone with an "R" stamp, but FRA requires you to do repairs following "an acceptable national standard" anyway.
Regardless of who inspects my boilers, I am still the one responsible to operate them safely.