When discussing details for any coin, which side is left or right? When looking at a coin, it's left side (to our view) is the coin itself's right side. This is driving me nuts when describing a coin.
I agree with @masterswimmer above. In the numismatic literature, I always see references to "clock face" (e.g. "...at the 8 o'clock position near the rim on the obverse one finds the privy mark of the Paris Mint..."). Also, if referring to the "right" or "left" of a device on the coin, I've also read things like, "...the eagle's right talons clutch a globe, while the left talons grip a sheathed sword..."
Clock face terms are more precise, but normally I see coins described from the viewer's point of view, so that "head left" means the head of Athena or whoever is facing to my left as I look at the coin.
