I just insured my truck for the first time since it's able to be driven on the road in the 2-1/2 years I've had it now. Granted mine is a lot newer than yours being a 1969 but it is a C60 with a 5th wheel , hydraulic steering and air brakes so it doesn't get more "commercial" than that. I have state farm. My agent came out took some pictures, fell in love with it and boasted what kind of shape it was in. I believe it was $100-150 for a 6 month policy. I am running historic plates and am limited. Basically I can't drive it everyday for routine driving and at 6mpg I don't want to anyways.