Only 13 Finer...

Adjustment marks were made at the Mint to bring the weight into precise compliance with standard, since they circulated at bullion value. Planchet weight control was not particularly great, so the Mint tended to cut planchets heavy and lessen the weight later.

This usually happened before the strike, so what you see here wouldn't happen. Indeed, planchet marks are more common on larger than smaller coins due to the greater pressure required to fill out the die of the larger coin - smaller ones filled the die much more easily.

The only thing I can think for this coin is that the planchet slipped through the process and was discovered heavy after it was struck. I cannot explain why they didn't just restrike it, unless it was assumed circulation would wear the marks quickly anyways.

I keep coming back to this thread. Boy, really has a lot of high end stuff.

Funny at first, I did not like the coin. But the more I look at it (thanks to the comments here), the more I am drawn to it. Even the marks don't bother me as much. Ah, where is that $52G I had laying around?

Another fun fact about adjustment marks on eighteenth century coins of the Philadelphia Mint, the positions created for the Mint workers who made those marks were essentially held by women. One of the first documented female workforces in the US government.

The adjustment marks were definitely done post strike as evident by the stars.
Very interesting indeed.

Normally, the devices sit on top of the adjustment marks. In this case, the graders have seen enough of them to recognize in this case.

By the looks of it, these were done quick and precise by someone who has done it many times before.

I would say the adjustment marks were done pre-strike. The clue on adjustment marks is that they may be strong on the devices such as on this piece, and will show crushing in the fields but will extend ALL THE WAY TO THE EDGE OF THE DEVICES. Under a glass it will be seen that the file marks were on the planchet first. The field areas of the die crush the file marks but they remain strong in the devices because of the lower pressure there. If the file marks are applied post mint they will scrape the devices, but the devices will protect the fields in close and any marks in the fields will not come all the way to the bases of the devices/lettering. (Unless the lettering is scraped away completely all the way down to the level of the field.)

If they did do adjustment post strike it would be indistinguishable from post mint damage and would be treated accordingly.