Just a strange thought. Did you weigh the coin? Is it possible that the scratches are adjustment marks from filing the coin to make the proper weight? I know that they don't look like the typical adjustment marks I have seen, but there was no directive on how it had to be done, the men at the Mint just filed the coins.
That's an interesting thought, but I don't recall ever seeing adjustment marks on a copper coin. Anybody else got more experience here?
Pricing on these is all over the place in XF40-AU58, according to PCGS auctions. As an AU details coin, I would say you paid close to full retail for it. If you don't want to lose money, I think return is probably your best choice.
What would be the weight of the holder and gasket for half cents? Unless you know this precisely and have a very sensitive scale, you wouldn't notice any difference.
I haven't either, but I am not an early copper specialist either. Since copper is not a precious metal and any difference in the value of the coin would be minimal, I'm not sure that the Mint would care to use adjustment marks on minor coinage.