Back in 1973 we had an eight year old 1206 that was in very good shape so we added a Hiniker Cab and these two 300 gallon saddle tanks. But we still needed more spray capacity to go with our 12 row planter, so we replaced the two 300 gallon tanks with two 400 gallon ones.
The front axle was then seriously overloaded so we added an extra wheel assembly to help carry the weight and smooth out some of the shock loading.
The wheel could be hydraulically raised or lowered as desired. It had a Chevrolet coil spring inside the pivot tube that enabled the extra wheel to carry about 1,500 pounds. This suspension allowed more than 8 inches of vertical movement.
Those of you who looked closely might have noticed that I added a second air conditioner. 35 years ago the a/c units were not too reliable, so I had two completely separate units. You can see the two compressors and both roof top assemblies! We used this tractor this way for several years until we switched (Sorry, Red Power Fans!) to a JD 4640 and a 16 row planter. Later photos show this 1206 tractor after we had removed the cab and replaced the fenders.