Well, now you guys have gone and made me make a username on this forum - and as you all know, I have no business being on a concours forum!
To clarify - the car appears to only have ever had two paint jobs before I got my paws on it. Mint green primer, factory silver blue metallic, then another coat of brown primer and the dark blue paint job. When we stripped the car, all parts of the car (sans a couple of patches and the lower quarters, which were apparently done when the dark blue paint got put on) had the same 4 layers of color.
While it's possible the car has been clipped, I doubt it. The frame is straight as can be, the cowl is perfect and unmolested (one of the very few original unrotted cowls out there, I'd wager), firewall unblemished, blah blah.
Interestingly, the inside of the shock tower cover is also white. The shock towers are the only two spots on the car where I have seen white paint. It is not overlaying anything as I picked off a flake and got down to bare metal.
What does it mean? Who knows! Wouldn't be the first (or the hundredth, or the thousandth) weird thing I've found on this car. She is just an oddity.