Anatoliy, here is an interesting coin for you especially: This is a Russian 1 kopek coin minted in 1757: However if you did look carefully, this is actually overstruck on a Swedish 1 ore coin!!!!!!!!!!! If you can't see traces of it, hint: look in the bottom of the monogram. You should see the monogram M, which is the ending word "1 Ore S.M." (rotate 90 degrees anticlockwise)
