i don't think one thread can answer all the insurance questions. Different states, needs and trucks.
Also it is usually very new members with insurance questions.
Insuring my Pinzgauer 712 (6x6) in New York was almost impossible , $4,000. a year.
When I got to new Mexico, they called it a pick up truck and insurance was a few hundred a year.
I think the M109 would have been easier in New York. here I had to become a business to get away from collector restrictions. They asked if i had a locking garage, not if the vehicle would fit through the door.
Rodger