If you get off all of the ozidation then I don't see why it wouldn't stick.
Anyone that's owned a patina car knows that the patina changes pretty quickly, and sometimes you want to preserve how it looks "now". Older single stage paint dulls out quickly unless you stay after with wax so it's a lot of upkeep. My '64 VW has the original paint and the spots that are worn through to primer have deteriorated pretty rapidly over the last few years. If I let it go a few more years then the light patina look would be a heavy patina look that I don't like as much.
I shot my '63 VW convertible with SPI Universal clear and added about 7% flattener so it didn't look too glossy. I've had a lot of people ask if it was the original paint at shows. Its holding up well after almost two years with no loss of adhesion or any change in gloss, all I have to do is wash it. It was very oxidized when I found it so I heavily scuffed it with red pads, then lightly sanded with 500 grit to knock down the orange peel.
I wetsanded/buffed a spot on the door to see if there was good paint under the oxidation. Looked good so I scuffed/sanded the whole thing.
Gloss level before/after drying.
