Can't see the back of the coin as it's set in the ring.
No, this isn't being sold for food.
crappy feeder albums?
Is there a way of removing the coin - i.e are there some sort of bent lugs at the rear. Normally these types of rings are mass produced and they set a coin into the ring and then put a retaining bezel over it which fits through the main body of the ring and they then bend the lugs over to keep the coin in place.
If you could see the back and it is is in significantly better condition than the front, it would give an indication as to whether or not the coin is genuine or not.
This page has a picture of a Sovereign as an example. The half sovereign is smaller. In fact this could confirm it - Gold Sovereigns are 22.05mm in diameter. Half Sovereigns are 19.03mm in diameter (from 1817 onwards).
Don't tell me, the guitarist from RHCP is selling some jizz stained underpants?