Gold Syracuse Drachm

I have what appears to be a gold version of the Syracuse Drachm. This has been in my possession for 30 years. It was originally mounted in a ring in the mid 1970s. I have no idea if this is a genuine historic coin or a copy/fake. Has anyone come across a gold version of what appears to be a very rare silver coin. It is the same size as the original silver coin and is very similar (though not identical on close inspection) to the images shown on this site. Can anyone recommend an assessor that could verify if this is a genuine coin or a copy/fake.