You can probably pick any Pre-1950 model of any brand and find the same thing. I have seen and worked on more Farmall H than any other model, and looked at all of them on every WHO Tractor Ride I have been on. In total probably well over 100. I have never seen any 2 alike. IH made close to 300,000 of them. One time I thought I saw one like another, but when I looked closely, they were different. Over the years, my dad probably had 8, and I worked on every one, and each was quite different. Same for all the JDs I've looked at. Maybe you can find 2 4020s alike or 2 4430/4440s alike, but that is newer than I look closely at. Probably Ford 8n or 9n are most likely to be alike, as old Henry gave you one choice, just like his Model T. Dealers still liked to sell options, like brush guards.