Nice to hear of another FGF owner just down the street from San Antonio.
I'm not too sure on the '68, but I was lead to believe all 400 optioned vehicles came with the hood from the factory. Now what happened at the local dealerships is another story.
But I'm sure someone else here can set you straight, or worst case scenario, you can order the PHS documentation on your car.
Hey, if yer ever in San Antonio, let me know, we've got a couple of really nice Pontiac folks here that love to talk cars.