Insure it as a a car with Hagerty. If something happens to it, you will never get you money back.
I have mine done this way. My GF gor in a small front collision with it, and the other drivers ins. co. was gonna total it. I called up my Hagerty rep, and got it fixed. Let them go after the other guys... In AZ it also allows to you forgo emissions testing (big cam/no cats), and 5 year reg renewal. Which is normally 2.