The final generation of Massey-Harris tractors, introduced immediately after World War II, included the 25-horsepower M-H 22 series, the 35 horsepower M-H 33 series, the 45 horsepower M-H 44 series and the 55 horsepower M-H 55 series. In 1952, the M-H 22 was replaced by the M-H 23 Mustang. In 1955, the 30-horsepower Massey-Harris 50 was introduced after the merger that created Massey-Harris-Ferguson. It was based on the Ferguson TO-35 and was also produced as the F-40 for Ferguson dealers. The MH-50 was available in several configurations: utility, high-crop utility, or row-crop with a choice of single, tricycle, or wide adjustable front ends. In 1956, the M-H 33 was replaced by the MH 333, while the M-H 44 was replaced by the M-H 444 and the M-H 55 was replaced by the M-H 555. These tractors were commonly known as the "triple series" and were mechanically similar to their predecessors, but featured new styling that included a slightly different hood design, chrome trim on the grill and hood, and a different color scheme. They were also available with power steering, live power take-off (PTO) and hydraulics. The Massey Harris triple series tractors remained in production until 1958.