I am looking to buy a lifetime issue Alexander the great drachm, I think every Ancient Greek coin collector should have one. I found this drachm that looks deacent for a reasonable price. However at the reverse I see near Zeus arm a squared hole and I am wondering if this is a countermark or is it damage? If it is a countermark it would be really interesting to know what could it be, if it is damage I won't get it. Opinions appreciated.
I started to doubt if it was damage or not, because it looks like it is a nice squared shape and also it seems there is something inside the square, a monogram or something. I hope someone can help further.