You need to do what makes you happy. If you are falling in love with the Grande, as you stated, then that gives it more personal value to you. It also comes down to are you going to do the work yourself or have it professionally done. If you are going to have a body shop do the body work and paint it and the mechanicals done by a shop, sadly you are going to have more invested in the car than it is worth. If you do it yourself, you will still probably have as much or more in it than it's worth if you sold it. If you don't care and just love the car and want it nice and plan to keep and enjoy it, then the return on investment doesn't matter. It all comes down to what you will enjoy most. Life's short and we all need to do some things that may not necessarily make good monetary sense, if it makes us happy. I, for example am doing a full restoration on a 71 Mach H code car that had no engine when I bought it, so it can never be a numbers match car. I have built a modified 351C M code for it that dyno'd out at 437 HP. I am doing all the work myself, but I will still have more in it than an H-code, "wrong engine", non-numbers match, color change, interior color change, up-optioned car will be worth. I don't care, because I am not going to sell it, it is exactly what I want in a 71 Mach 1. I have other cars that are worth much more than I invested, that doesn't matter because I'm not going to sell those either. It all comes down to what makes you happy.