I have a 2 escudos gold doubloon that I purchased from a very reputable seller on eBay some years ago. For whatever reason I never thought to weigh it at the time as I trusted that it was legit. Having just purchased some accurate scales, and remembering this coin I bought back in 2011, I weighed it and it is coming up light, 6.27g instead of what should be 6.77g. Does this mean it's definitely a fake or did they vary a lot by weight, half a gram seems an awful lot though for a small coin.