This pistol is one of only four prototypes of the deluxe grade World War I commemorative line of pistols which were released beginning in 1967. The deluxe grade was a limited release, with only 25 of each of the four commemoratives being made. Each of the deluxe grade was hand-engraved by legendary Colt engraver Alvin A. White. This example generally shows the characteristics of the deluxe grade Chateau Thierry Commemorative which was eventually released to the public. The included copy of a letter from A. A. White Engravers Inc. goes into great detail discussing the near full coverage, masterfully executed, floral scroll engraving, Chateau Thierry machine gun nest scene on the left of the slide, and World War I commemorative banner on the right which has a gold inlaid border. The gold inlay continues with bands on both sides of the slide at the muzzle and in front of the serrations, the prototype serial number "WW1-4", as well as a small plaque under the right grip marked "COLT A.A.WHITE ENG.". Also engraved under the right grip is the pistols original serial number "300905-C" (dates to 1966) and "AAW". The letter goes on to state that this is one of only two of the commemorative series, prototype or otherwise, not chambered in .45 ACP (the other being prototype WW1-3), that this is the only prototype with a straight mainspring housing, and that the grips were later provided by Colt upon return of the prototype to the engravers.