I have a Gold Polish Coin with Sigismund III on it. Last year I sent it to Heritage Auctions for an appraisal and they didn't want to do anything with it and said it could be fake. I've since had it tested to be real gold so I can't understand why anyone would fake a real gold coin. On the front of the coin it has the king and says SigisMVN.III.D.G....next to that is a box with what looks like a backwards B and a symbol below it.... then REX.POL.M.D.L....On the back it reads GROS.ARGEN.SEX.REG.POLONI...it has 3 shields and an M above them. In the right sided shield it looks like a bird with it's wings stretched out. In the left shield it looks like a knight on a horse and in the bottom shield it looks like the tip of a spear.

To the right and left of the bottom shield it says 1601. Any help on this would be appriciated.