Frenching=
That's what my dad always called it when guys would sink a light or body fixture into the lines of the body.
If you were to sink your gascap into the body, creating a pocket for it, you would say it was frenched.
A common example of frenching would be the guys that took the bullet tailights from mid-to-late-50's Caddy's and put them in groups across the back of an Olds or Chevy. The effect looks kind of like the little taillights are each sitting in an oversized body-colored socket. Kinda like a deck screw in a too-large pilot hole only cooler.
I'm making a bit of a mush of this, so I'm going to consult my Pappy for some photos. I'm sure I'll have something by tomorrow night.
As far as frenching those scoops goes, a better way to put it would probably be to fair them in. More like just putting holes shaped like the openings on those scoops in the hood itself, and then having the metal go inward to finish the effect a little better than just sawing a hole.
My hotrod (not nearly so cool to start with as yours) has a large triangular hole in the hood where the bugeater sticks out. It is cool enough, but not as finished looking as a dog-house or a true scoop is. Your ride I'm betting has plenty of clearance under that gorgeous domed hood, so a scoop that goes inward would add a sinister look that doesn't disturb the original lines. I think this approach would accentuate the "antiqueness" of the car, and still make it look bada$$ & fast. You'd get a ram-air effect if you do it just right.
Just my two cents though, whatever you do decide to do, that car is going to be too cool!