I've seen choppins car...what a great car!
So have I and I agree with you on all accounts, VERY cool car just not really my taste. This is a good example of a neat car (I really do appreciate it for what it is) however, if it were for sale I would'nt pay as much for it as I would for it's unmodified counterpart all other things being equal.
On the flip side there are those who prefer modified cars and would jump at the chance to own a cool retro car like that, and someone may be willing to pay beyond what they'd pay for the same original example, but consider that when you are are selling a customized car, you will likely be dealing with a MUCH smaller market segment and the chances of finding that "one guy" are pretty slim. Of course in that case the car was already modified when it was purchased by the current owner, there is no descision to make concerning modifications, it's already a done deal.
What to do with Choppins car? Personally I'd leave it alone and enjoy it (Adding that Hemi certainly won't hurt it though) because restoring it back to stock would probably cost more than it's finished value, especially if it's not a numbers matching car. BTW. I'd also save the vintage Keystone wheels and MT tires, they will add to the Nostalgia value IMO.