My '68 was spot welded but has holes with 1/4" nuts welded to the under side of the cowl. So they were set up to to be bolted on but the assembly line welded them. I'm going to weld a stainless hinge to my windshield frame and bolt it to the cowl. I think this could be done to any early Bronco. The heads of the bolts need to be short enough to allow the windshield to be bolted upright with the dash knobs.