Starting in September of 1920, the Ordnance Board began to make suggestions for modifications to the Model 1911 pistol, and by April of 1923 OCM Item 2890 was standardized and recommended by the department. Some production issues arose throughout 1923, but by January 1924 the first "Improved Models" were being delivered and were also known as the Transitional Model 1911s. While they retained the nomenclature markings of the 1911, they were equipped with the signature features of the 1911A1 which included the dished frame sides, shortened trigger, elongated grip safety, and arched mainspring housing. Fitted with round blade front and flat top notch rear sights, with the two-line, two-block address and patent markings divided by the Rampant Colt logo on the left side of the slide, "MODEL OF 1911.U.S.ARMY" on the right, and "H" above the firing pin stop plate. The frame bears the circular Walter Gordon "WTG" inspection stamp, with the short milled checkered trigger, wide checkered hammer, long grip safety, checkered mainspring housing with lanyard loop, a conjoined "HP" marked barrel, and an unmarked two-tone magazine.