I thought US quarters and the english 10p were pretty much the same size?
I have a UK and US version (for my up coming trip to the states - did I mention that already
) - and they seem pretty much identical. In fact I was a little disappointed as I was expecting the edges of the US coin stack to include the brass that is found in the edges of US quarters - at the moment placing a quarter on top isn't very relastic at all.
I think I will follow seiges advice about antiquing the edges.