The photo sure makes this look silver, not gold. And I'm no expert on Atocha, although I have been an Atocha fan for many years.
I can say that I agree with the previous post - very few gold coins were found. Mostly silver.
If this is gold, chances are that it can be verified by photograph, and perhaps even a replacement certificate created.
YES, fakes and "recreations" of the silver coins have been made, so there is no reason to expect that fakes of the gold coins haven't been made, too.
Look at other bezels online. This bezel does not look even close to other Atocha coin bezels.
Without a certificate of authenticity, I'd stay away from this.