Once you fix the problems whos going to spot in the paint and blend it? Which isnt going to be easy on that old of a car. you prolly wont be able to just bring the vin to a paint shope, and shoot what they mix up. you would have to have them put a surface camera on and take a reading and mix the paint based on that. But this isnt a show car so i would say just mix up the paint off the vin and shoot it. then buff the entire car so the new paint doesnt look completely out of place.
Btw they dont make replacement wheel arches for those or hardly any cars for that matter. Usually what we do is buy up a bunch of old cheap SOLID fenders for $5 a pop and use a body gauge to find a section of a old fender that fits the arc close enough and use that for a replacement panel.
Or bust out the english wheel and make one from scratch!