New Rear Body Panel: Leave factory seams or finish smooth?

68s had the reverse lights in the taillight...no holes for reverse lights in the valance. Maybe you have a '69 valance?

The valance came with no holes at all. I believe it said it was a 68 big block (formula S?) I just figured on drilling the holes for the reverse lights with a hole saw. I don't see any other differences in the sheet metal. Seems to fit great.

Am I missing something? -wouldn't be the first time!