There are of course proof versions, but i won't talk about them. Here are some post victorian varieties:  Some Victorian and Edward VII farthings have a dark finish Some 1926 halfcrowns have no colon after OMN The 'H' varieties and 'KN' varieties of British pennies From 1949 onwards, all British coins didn't have Ind;Imp on them The 1940 penny sometimes had a double exurgue line 1955 and 1956 farthings had thin rims on the reverse From 1954, British coinage no longer had Britt.Omn on it Some of the 1954 halfpennies had large border teeth  I won't tell you about gold coins as I am not familiar with them. I hope this is what you are after and it helps. As mint_mark says, try to get that Collectors Coins book, it does have lots of different varieties in it. William