My two cents, I have done six frame off restos on GM cars and two rotisserie restos on Mopars. Mopars have fender tags, and unless those are removed or altered, future owners will always know the cars true identity. While a car is only original one time, they can be restored an infinite number of times. So, if you wish to take a basic Grandma getter and paint and badger it as desired, you have not done anything that permanently alters the car.
GMs are different, with out original paperwork, which very few still have, one can create a clone which can be difficult to detect. I own a 67 Camaro, plain jane, 210 hp 327 with two speed power glide, that my father gave me in 1972 when I turned 15. Im collecting parts to turn it into a 396 SS/RS car. I think I have owned it long enough to do what the hell I desire.
My 68 GTX restoration will be as bone stock restomod as possible, color and all. My 71 318 plain Jane grandma getter Charger, will be as gaudy as possible, screaming bright paint, jacked up, decals galore, spoilers, all the stuff Mopars had back in the day that we in the south did not like back in the day. That's what has attracted me to Mopars today as I wish I had one of each of those wild homosexual colored cars. Love em, do what makes you happy.....