Thanks for your reply fioti; I forgot to mention the size which is 18mm, 1.3mm thick and it weighs 5.8grams. Not sure what a 'fantasy piece' is? Would it have a low gold content or just be all brass? Mike.
I suppose the best way to describe something like this is Costume Jewellery. The double sovereign piece shown would have been worn on the watch chain (also probably brass)of someone who liked to look good, but couldn't afford the real thing. And in those days, that meant maybe 90% of the population.