Hi John,
I was in the garage today and removed the clip on my 67 survivor with a UO radiator. I assume you meant the clip on the right side bottom that hooks to the core side and the other clip side, using an arrow shape protrusion, that gets hooked into the radiator side mount. There is definitely full coverage paint on the radiator surface under the clip. Inspecting the clip itself it has no traces of ever having black paint. It has an evenly oxidized finish exactly like the dry and oxidized texture of a part that was originally phosphate. The left side smaller clip is definitely zinc phosphate.
Mike
