That last picture (proofmeter) "prooves" that it is a 51 or 52, which in my opinion was the high-point of the Ford tractor company for many reasons. Most importantly, these were the most refined form of the N-series. It was not until Ford introduced, the N's Successor, the Jubilee, in 1953, that they began to give up ground to the competition until eventually going "belly-up" and getting abosorbed by Fiat. To me, the Jubilee was a step backward, turning a light, nimble, durable, in a class by itself, 2-plow tractor with excellent fuel economy, into a clumsy, awkward, not-too-efficient, weak-hydraulic, also-ran, 2-plow tractor, that had little hope of keeping up with the competition of the time as they too adopted the 3-point hitch. Part of the appeal of the 8n was the ease at which it could be hitched/unhitched from an implement. Even without a quick hitch, I can have that job done on my 51 8N in under a minute, mainly due to the tractor's light weight, and convenient location of the lift lever. When I compare that to my nieghbor's 53 Jubilee, that I did some work with when I was young, that job was much more difficult because of that tractor's increased bulk. The 51 is my real favorite and I will admit that may be partially due to the fact that it was the first tractor I owned. I wouldnt be too surprised, if Ford tractor co. was like several other OEM's with whom I am familiar, that "questionable" parts found thier way onto the 52's as the company was tooling up for the completely redesigned 1953 models. I guess that would make the 1951 model 8N, coincidentally my first tractor purchase, which I still own, the true "high-water" mark for the Ford tractor company. If any one has any reason it should be some other year or model, feel free to tell us why. One things we know for sure though, your choice wont have as good of parts availibility.