

https://en.numista.com/catalogue/pieces9394.html
I think this coin could qualify for VF, which has a catalog value of $400. The diameter and thickness are exactly correct according to my digital caliper. I don't currently have a coin scale, but my food scale reads 8 grams (it doesn't have tenth-of-a-gram precision), which at least accords with the specifications on the page. I don't see any casting seam along the edge, and the coin looks old to me. The bargain bin I found it in frequently has older coins (I have found a few 18th century ones) from people who have sold their collections to the shop.
Thoughts on the likelihood of this being authentic? If so, what would my next steps be, assuming I want to sell it? I assume I should submit to a TPG - is NGC the best choice for world coins? If they do authenticate it, are there better places to sell higher-value coins like this than eBay?
Thanks for your advice!