上海公共租界巡捕房
After receiving drawings of the proposed knife from its designers, prototypes of the V-42 were submitted by three knifemaking companies - Camillus Cutlery Co., Case Cutlery, and Cattaraugus Cutlery Co.. Captain Dermot Michael "Pat" O'Neill, the First Special Service Force's close-combat instructor and a former Detective Sergeant of the Shanghai Municipal Police (the same police force in which Fairbairn and Sykes had served), recalled that Col. Frederick personally selected the Case prototype and gave authority for its acquisition.