Hola!
My friend was offered these 8 reales 1776 OM. It seems fake to me but he want to hear more comments.
Unfortunately he has only these photos.
Certainly it’s not a 8 reales produced at Mexico mint 🧐 and I don’t recommend your friend to buy it.
However there are many contemporary counterfeits of these coins and it may happen to be one of them (but I still doubt it). And if you’re eager to know the truth you may need to talk to Robert Gurney about it, he is registered here with his username @swamperbob.
My buddy just told me the coin is magnetic and has low weight, thus he refused to buy it.
Mucho gracias!