Welcome to Coin Community, WinstonSmith. With a mintage over a million, this isn't a particularly rare issue, so its' value won't greatly exceed melt. The obverse has undoubtedly been polished. As easy as gold scratches, the lines we see here which are normally caused by a brush could have been caused by cloth. Either way, that destroyed any additional numismatic value to the coin.
It's a shame. Gold does not corrode and chances are whatever they wanted to remove would have rinsed off. They probably just wanted to "make it shine."