Integrale
True Classic
Odie, I saw a classic "exotic" that reminded me of your wing design ideas. And it has a couple of other elements that might interest you as well. Take a look at not only the rear wing size/location/proportion, but also the front one (not the best picture of the front, but this version was very rare and there aren't many pics of it to be found):
View attachment 24289
I also think these wheels would look great on an X1/9. They are 15" (best size for an X in my opinion) and with BIG fender flares you might be able to actually fit them. However it would be very expensive to get ahold of a set. I wonder if there have been any knock-offs in this style?
Mickey Thompson makes a similar wheel, unfortunately they are only 5 lug and up.
https://www.jegs.com/p/Mickey-Thompson/Mickey-Thompson-Classic-III-Polished-Wheels/2351911/10002/-1