"Original" might suggest that everything on the truck is what it came with when it rolled out of the factory.. crappy tires, lugbolts that could break at any time, and spongy brakes with rusty lines that will probably rupture at the least opportune time.
"Restored" probably means to them that the truck has been properly restored.. new brake lines, rebuilt MC, fresh tires and pads, etc.
If I was an insurance guy, i'd be real spooked about insuring a 50 year old 3,000+ lbs rustbucket.
Not to say your truck is a rust bucket.. but it's not like they're comming out to inspect the truck before they insure it, so they have to assume the worst.
