If the OP's story is correct, then it's highly unlikely that the coin is genuine. Genuine ancient bronze coins do not come out of the ground looking like this, especially in an acidic environment like Pompeii; a coin can only look like this after considerable restoration efforts.
Sorry Sap,
I do hate to disagree with a fellow Aussie, but I feel I must.
I have
had the benefit of seeing a very large number of coins
from dig sites, both formal archaeological sites, and those from
legal metal detecting areas.
I have also
had the benefit of seeing hundreds of excavation
coins in the various museums and universities I have visited
during my years researching various numismatic subjects.
In particular, I have seen images of coins that were most
certainly from Pompeii, in various states of wear and corrosion
depending on where they were found. I was also shown what
were claimed to be a few of the coins themselves, though I
cannot verify this from memory alone, I will (firstly) have to try
to find and then (secondly) check my notes (I think this was on
one of my many
Italian museum visits, though it was a while
ago [15+ yrs?]).
I even think that there was an article about the coins from
Pompeii some time ago, with images (
The Celator?). Not sure.
IMHO, this coin appears to be genuine, the corrosion on the
surface appears real, and whilst I admittedly cannot "know"
either way, based on present information I believe this coin
to be real as claimed by the OP.
We'll have to swap notes/stories over a quiet beverage or
two next time we are both in the same city. Do you know
about the monthly ancients meetings in Sydney (ASAN)?
Walter
Holt