I repaired the shroud on our '65 Caravel
. It cracked and was coming apartin the area where it is held down by four bolts. I removed the shroud and used fiberglass repair process, repairing on the inside of the shroud, I made it much stronger than it was to begin with.
Then...I didn't want to trust the original method of hold down. There was a piece of 2" angle. the kind with all the holes, across the front where the unit attaches to the roof. I cut two pieces of 1/2" all thread 4"long, and installed them about 4" from each end of the angle, protruding out over the roof. I cut two pieces of 5/8 automotive heater hose and slid one onto each piece of all thread. After painting the shroud, I installed it, sliding it under the heater hose, then back and down onto the four bolts in the top.
Now, going down the road, the lift created by the air passing over and under the front of the shroud can not lift the front of the shroud.
that was five years and 80,000 miles ago. No problem