[Tx Firefighter]

Sandblasting is the best way to get one truly and thoroughly clean.

For paint, there are several different options. Places like Eastwood sell frame paint in aerosol cans.

My father in law uses Caterpillar tractor black frame paint. It's about 40 bucks a gallon and ready to spray.

Myself, I use urethane paint just like the outside of the body. You can mix it with a flattener agaent to get the right sheen.

I'd say best option would be to powdercoat it, but it can get pricey.