Instructions
Examine the outer rim of very old pewter plates and the handles of old ale-pots and tankards. Look for impressed initials -- the "touch mark" or stamp of a registered pewterer. Crude initially, then becoming more elaborate over time, these markings appeared on antique pewter from the 1500s until the 1820s.
Scour the base for other markings. On early pieces you might find an X or the word "superfine"--both indications of best quality pewter. A rose and crown is a mark that appears on English export wares in the 1700s. In the 19th century, items used as measures were given a date code and a variety of regional emblems, for example a thistle for Scotland.
Check for a maker's mark on later pieces, especially those with a strong, commercial design. In particular, look for the names Liberty's and W.M.F. Under the Tudric brand-name, the London store Liberty's produced stylish pewter in the Arts and Crafts manner. These pieces are stamped with the store and brand names and sometimes the words "English Pewter." The renowned Art Nouveau creations of W.M.F. bear the German firm's initials or sometimes a running ostrich inside a diamond.