I agree with BA, the Oliver 70 begin production in 1937 as the 4 speed row crop, 1944 with addition of the 6 speed gearbox in row crop model, 1937 the 4 speed standard was introduced and in 1944 came the 6 speed standard.
Serial Numbers 4 speed 1937 216 926-219 644 ending in 1944 244 711-254 040
1944 245 041-250 179 ending 1948 262 840-267 866. The standards begin in 1937 with serial 301 803-302 083 and ended in 1948 with 314 221-315 420. There was also a Oliver standard 70 used for airports and was labeled the Oliver Airport 25. There was also an Oliver manufactured . These were the true Oliver 70&#039;s. From the introduction of the 70 in 1935 it was labeled Oliver Hart Parr until 1937 when the Hart Parr was dropped from the name. Oliver Hart Parr serial numbers 1935 200 001-200 685 until 1937 208 729-216 925.
Most of this infomation was gathered from AGuide to Hart-Parr Oliver by Larry Gay.