Hmmm.... When I first got my '64 (I was 16) it had just had body work done to the rockers and rear fender flares, so it was primer grey from the trim in middle of the door down. The rest of the paint was oxidized and beat-up looking (body was A-1 though), so I scuffed it all and shot it with a dozen cans of cheap grey primer. With the nice chrome trim, bumpers, grill, and nice rims, I thought it looked cool. I even got lots of compliments (delivered pizza
). I drove it two years after that, and if I ever got a scratch or whatever, I just scuffed and reshot a little patch. The flatness of the primer was really forgiving, it didn't look blotchy at all. It sat for 5 years after I parked it, and when I actually started to restore it 2 years ago, I was surprised at what good shape the original paint was underneath.
If the above recommendations of sanding, and waxing doesn't help much and if it was temporary until you had the cash for a proper job, and you wanted a change, or to give your body a more "consistent" look to it, I say go for it. Maybe a black primer? There are probably a half-dozen rods in my town that are sporting "primer" finishes.
A friend of mine drove his '68 Malibu for couple of years and it was some sort of reddish-brown primer with a white top, and with some nice chrome rims with fat rubber and it looked very cool.
I know it wasn't the "proper" thing to do, but with the limited funds I had, it looked 100x better than the weathered, beat-up finish it had when I got it.
Good luck!