Ave PBA,
I have never seen a ring exactly like yours.
Is there any remnant of glue within the bezel crown? If so, it may have
had semi-precious
stone?
Here's an example of a shield-type ring, ca. 900-600 BC, that are currently attributed to
Bactria.
This particular ring and a few others were actually featured on an NCIS episode earlier this year. Who knew!
Best regards,
Kevin