It seems to be a very rare coin, I included a link to one selling in an auction house. From past sales, I seen them go for from 7,000 USD to 2,500 USD in varying quality.
I would advice having it sent to reputable grading companies such as NGC or PCGS to get it authenticated and placed in a slab, where more or less, it 'assures' by 'the experts' that the coin is genuine.
I don't usually deal in high priced pieces, so best to wait for a bit more if someone else can help you out get a better estimate for your coin, and any additional advice.
Just to let you know, [if you don't know already] no cleaning is needed whatsoever for such a coin, as that would have its value drop significantly.