1917-S Walking Liberty Half Dollar. Reverse Mintmark. MS-65 (PCGS). The conditionally challenged 1917-S Reverse Mintmark issue is a much rarer Walking Liberty half dollar in Gem grades than the generous mintage might imply. This is an exceptionally beautiful example bathed in a faint medley of russet and champagne-gold iridescence. The luster is lively beneath the toning and remains fully composed even across the more exposed areas of the design. PCGS# 6573. NGC ID: 24PU. PCGS Population: 52; 14 finer.