Interesting post.

I have a 1966 4020 and am quite impressed with the design quality of that machine.  Latter tractors certainly were improved in form and function, but not as well built.  The little things like the front axle hub dust cap were almost over-designed, complete with o-ring seals.

I don't have a tractor that is more fun to "play" with than the 4020.  I'll keep it just to experience the feeling of that era of farming.  I can only imagine what a joy it was to buy a new one to replace whatever was being used before it.

My first job was working on a farm in 1969, and I started my own enterprise in 1971 with a few hogs.  The farming during that era was different and more compelling to me than the farming of today.  I must like living in the past, because I would return to farm life of the 70's in an instant if given the economic climate to do so.  Oh, well.