Many years ago I talked to the owner of AAR fiberglass at the Mopar Nats. He said many of the 68 SS/H cars were using his hoods and that they were bolting the scoop on. The reasoning is that a bonded scoop eventually cracks at the joint and ruins the paint job. Lotta force generated at 150 MPH!
One thing to look at on the Feather Duster hood is the joints between the aluminum and steel parts as the dis-similar metals promote corrosion, especially in the rust belt. Also the hinge bolt area on the hood. I have a Dart Lite hood sitting in my garage with these issues.
Other than that, your plan is good. But, my personal opinion is that the twin snorkle scoop is more period correct for a 70's car.
