The post war 6" Masterpiece and 4" Combat Masterpiece had the same frame and tapered barrel profile with different lengths and front site styles until 1950 when the 6" wide rib "Heavy Masterpiece" appeared ,
Initially both versions were produced simultaneously but by 1955 the 6" wide rib Masterpiece had totally supplanted the 6" tapered barrel version.

After 1955 the 4" CM and 6" Masterpiece had a frame design that did not interchange because of the barrel profile where it meets the frame.

During the dash 5 revision the Model 14 and 15 frames finally shared the same frame but again had different style barrels.