Hrmm, somehow when Elmer Fudd says it, it sounds less naughty.
All fiberglass is going to have some sort of fitment issues. I don't think there has been a hood/trunk lid/scoop/misc_part_001 made of fiberglass that hasn't had to be worked to some degree in order to fit the way most of us want our stuff to.
I bought a Shelby hood for my 67 from Mustang Depot and was very pleased with it. It cost a little more than some other places, but you get what you pay for.