I think the value is in the eye of the one that will buy it. I think you have a good example of a 71 demon with the info you gave. If you are looking for max value, you need to restore it back to original but still you will need to have that one person looking for your car. I would make your car your own, enjoy it and when it comes time and your changes are tasteful, it will bring the max value it can. Just my 2 cents. Happy Moparing :)