What Type Of Counterfeit Is This 1787 8 Reales?

How much does it weigh, and do you have pictures of the edge?

If you have a way to do a specific gravity test, that would give more information on whether it was counterfeit. By looks alone my initial thought is a genuine coin with tooling on the date. Potosí produced some poor quality coins and I have bought a few in hopes of a counterfeit, but they have checked out for me so I've quit unless I see a really obvious one. Nice looking coin!

Looks like it was cast and then artificially aged.

Still scratching my head on this one, might have to send it to PCGS or NGC and see what they think. My gut feel is its wrong but as noted they do look funky from Potosi.

I also think that the aging does not look natural. Only the high points show little oxidation. As if wear from handling after the oxidation. But the coin surely did not circulate to be worn in more than a century.
If it was cleaned then the flat fields should also not show oxidation, only the corner areas should.

There are some indications of possible cast. The undefined die crack over the P of P.R., the lump of metal in the nose. Over the S of HISPANIA. But I dare not judge. Would regard as suspicious to be better examined in hand.