1915-S $50 Panama-Pacific 50 Dollar Octagonal (rev) (1216-4458)
Heritage Auctions (image); U.S. Mint (coin)
Image (2015)  coin (1915)
Heritage Auctions <a rel="nofollow" class="external text" href="https://coins.ha.com/itm/commemorative-gold/classic-commemoratives/1915-s-50-panama-pacific-50-dollar-octagonal-ms67-ngc/a/1216-4458.s">Lot 4458</a>, 7 January 2015