Here is a good comparision examples of the George Sisler W551. The first one is authentic, the second one is one of the blue captioned reprints.
http://www.ebay.com/itm/GEORGE-SISLE...UAAOSwP0RXh9bg
http://www.ebay.com/itm/1921-W551-St...gAAOSwxndXTiYN
Note not only the blue caption, but also that the colors get really funky in the reprint. Check out what is going on with the shadowing area on Sisler's cap in the original versus the pyschedelia of the reprint.
Brian