Most circa 1890s gunmetal putters have a straight blade.  On this example, made by Willie Park, Jr., the blade has been given a slight curve, heel to toe.  Many of the long nose clubs, including a number of putters made earlier in the 1800s, had faces that were also gracefully curved heel to toe. And there were putters made years later with similar curved faces.  

The shaft and grip are original. The shaft is stamped "Wm Park", and the head "Wm Park, Maker, Musselburgh" in Parks early oval stamp.  This is a very nice club, showing little wear, with a unusual feature almost never found in a gunmetal blade putter.