WI had no title or plates anything under 3k gross quite expensive over 3k though and required yearly tags. mi has permanent plates for non commercial. When I moved Had to get a weigh ticket in the UP took it to a lumber mills scales Wi title didn't have weight of trailer title gross or empty. I guess they were also supposed to inspect. dmv let me title with just weigh ticket.
Can it be thinned and sprayed with a hvlp gun, curious for my knowledge.Same in SC, but what you save in registration you spend on locks to keep the trailer from being stolen. Lots of folks have come back from a day on the water only to find their trailer unhitched and gone. I prefer Virginia's system of a one time payment for a permanent trailer tag and a title so a thief cannot register a stolen trailer.
I use Chassis Saver for jobs like this. It is a less expensive Por-15 clone. The nice thing about those types of coatings is you do not need to get down to clean metal and the manufacturer recommends that you leave any rust that is not loose or flaking to increase adhesion.