Developed in the 1970s, the Rock Island M15 was conceived in response to a shortage of Colt 1903/1908 pistols in Army inventory for issue to generals as a distinctive sidearm. Working from stocks of 1911/1911A1 components, Rock Island essentially produced an in-house custom variant of the Colt Combat Commander pistol. The overall markings are consistent with general production of the M15, though the serial number reads "Serial No. GO" with no following digit; the initial prototype used "GO Model 1" as the serial number marking, and after a discussion with higher brass (who were concerned that "Model X" would be read as a model designation instead of a serial number) the arrangement "Serial No. GO" was used as the prefix for production M15s, the first two issued being "Serial No. GO 1" and "Serial No. GO 2" respectively. This pistol can be seen on page 121 of "U.S. Military Automatic Pistols 1945-2012" by Edward Scott Meadows, where it is called out as a "General Officer prototype with third type slide and serial number markings". Serrated high rise blade front and square notch rear sights, "General Officer Model/RIA" on the slide, sharply checkered frontstrap, serrated and checkered backstrap, checkered hardwood grips with a blank inscription panel on the left and Rock Island "crossed cannons" emblem on the right, serrated spring plug, spring-loaded recoil spring guide, chrome plated barrel, and an unmarked blued magazine. Provenance: The Edward S. Meadows Collection; Property of a Gentleman