I thought Massey Harris ended production the end of 1957 with the end of the 333, 444, & 555 -- but the Colt ended in 1954, the Pony and Mustang ended in 56 and the Pacer ended in 57. Ferguson brought out the New F-40 in late 55 and ended production the end of 1957. Ferguson built the TO-20, 1948 through 51, TO-30, 51 through 54 -- these were all Gray Tractors. The TO-35 came out in 1955 and the sheet metal was Gray and the Engine & Chassis was Dark Green. In 1956 and 57 the F-40 and TO-35 were Cream colored sheet metal and the Engine & Chassis were Gray. In 1955 Massey Harris introduced the Massey Harris 50 -- which was the F-40 Ferguson Tractor and it was Painted Red wheels & sheet metal with Bronze Engine & Chassis. (I think i was a darker Bronze than the 333, 444, & 555, or maybe many of the Triples have been repainted a lighter Bronze or gold.) In 1958 most of the Dealers that were left to sell Massey Ferguson and Ferguson 35 Tractors. The 1958 TO-35 was painted Red sheet metal and Gray Engine & Chassis, in three models, Special, De-luxe & Diesel (De-luxe).Because the Pony, Pacer, Colt & Mustang were no longer being built the TO-35 was the smallest Tractor the Dealers had. In order to compete with other manufacatures they built the Special (Special low Price) Tractor. The Special had 10 x 28 rear tires, the De-luxe had 11 x 28. Many of the following items could be orderod on the Special but were standard on the De-luxe as: Lights, belt pulley, power spaced rear wheels, foam padded seat, 2 stage clutch with live PTO and live hydraulics and 6 speed transmission. tractormeter & fuel gauge. The Ferguson TO-35 was built for Massey in 1958 through the 1st half of 1960. It would have a Ferguson badge on the front of the hood and a TO-35 Ferguson Serial Plate. The 55 through 57 had a small Ferguson name plate on each side, toward the rear of the hood (1" x 8"). The 1958 - 1960 TO-35 had a decal on each side,a little toward the rear) of the hood (only a 1" or 1.5" tall) Ferguson 35 Special, Ferguson 35 De-luxe or Ferguson 35 Diesel (about 20" long) and a Ferguson badge on the front of the hood. In the middle of 1960 this Tractor become the MF 35. Massey Ferguson badge on the front of the hood, MF 35 serial plate, a Massey Ferguson 35 Decal on each side of the hood with a small Ferguson 3 point Decal toward the rear of the hood and a small Special, De-luxe, or Diesel decal under the Massey Ferguson 35 Decal. Some of this was relayed from a Ferguson Collector so I hope I got it right. Also TO-35 SGF 183517, I could not find a key for the letters- I did note on the Nebraska Tractor Test of a Ferguson TO-35 the letters SGM, this Tractor had a dual stage clutch ???? All of the MF Tractors had Red sheet metal & wheels and Metallic Gray Engines and Chassis. 1958 MF 50, MF 65 - late 1958 MF 85, MF 88 - 1961 MF 90 Super. 1959-62 MF 95 (MM - 425 cu in - 78 HP). 1959-62 MF 98 (Oliver 3-71 GM 2 cycle Diesel - 85 HP). 1962-65 MF 97 (MM - 504 cu in - 101 HP). Jerry