Looks like a repaint to me. Maybe it was a real "barn find" and the sparrow shjt ate the o.g. lacquer.
If some of it got repainted, it was done fairly well, although I did notice some odd checking and not so factory-looking paint in some areas. Can't speak for over the border paint, but by 1987, base/clear was widely used by GM across their entire lineup. On this car, there seems to be a ridge of clear build-up around the gas tank flap opening. That's weird. Of course, it was built in Mexico, so no telling what QA stuff they did there. I looked at other camino pics on the net and none of them had body colored radiator supports. Something does smell a bit fishy about this vehicle. WHY paint the radiator support blue? And it looks like the hood latch got painted, too. It presents well and it certainly doesn't seem to show it's a high-mile car trying to fake everyone out as far as mileage, but there are some things I have questions about.
Besides the questionable 2-tone and side stripes (I'd like to see the SPID) didn't elky's also come with rock guard on the bottom as well as "run of the mill" cars in 1987? This car has none anywhere I can see.
It's currently at 12,500 and IMO, that's about what I would say this car is worth. I'm betting it's going to go higher by next week because- El Camino- but it's not a Royal Knight or SS or any of the more gussied up packages. The only thing this car has going for it IMO is the 305, and that's only because then you can drop that GM 383 crate engine in there without much trouble. Doesn't even have an OD transmission.