My Dad had a truck that this similar thing happened with. A 1976 C30 Crew Cab. The body shop added a hood scoop, filled all the body molding holes, and grafted a spoiler on the roof. They used this new product called Lord Fuser which was a glue like bonding agent. It shrunk really bad so all the body work had to be redone after they painted it. It was a bad deal. Luckily you caught your pre paint.