Sorry I did not finish my post below and thank everyone for their input. I have 1958 Ford Workmaster with 651 on the hood and above the serial number. My father purchased this new in 1958, when I was 16 yers old and I was the first to drive it. I drove it off the truck. Dad sold it to me in 1986. It is still all original, except for tires. I have owned most of the other models mentioned. Someone asked what is my question. My question is how many people have actually seen a true 651. Models such as 640, 641, 840, 841, 860, 861, are very common. Other than my tractor I have only seen one other 651. I think they are a bit of an odd ball, being 5 speed no live PTO. Dad did not need LPTO as our New Holland hay baler had its own engine. None of the other PTO operated implements needed live PTO . Dad always hire custom operators for larger jobs. Thank you.