Michael, if you're unaware of these fakes you might care to look at alibaba.com.
It's a supplier listing from mainly China. In the past few months there have been listings for, among others:
1792 countermarked dollar
1763 Northumberland shilling
1864 florin
1893 sixpence
1935 crown
Mostly for a minimum order of 100 pcs.
These are not necessarily a problem for experienced collectors but the fakes are getting better and better. Take a look on CCF particularly at Swamperbob, a man who knows more about fakes and counterfeits than anyone has a right to. We are lucky to have him here, his expertise has helped all of us. If you haven't found the fakes yet, you will.