You're right that the stock hood has a large somewhat oval cut-out on the bottom side. I have 3 hoods, one being NOS, and they all have that cut-out. Not so sure how it would work trying to go through both layers of fiberglass if there's space between them. I'd probably make a cut-out. The two plates would certainly spread the load out on the single layer of fiberglass, and I wouldn't think it would be a problem. Trying to tighten the 2 layers with a space between them would likely distort both sides and be very visible on top.