Little know large 4-wheel drive tractor

If anyone has seen one of the Knudson tractors I would like to know. They are very rare and as I understand they were made between 1981 and 1983. There were five models they were the 220, 260, & 360 that were the smaller models that were painted green color and were made in Crosby, North Dakota. The 4400 and 4360 models were the bigger models with 855 Cummins engines and yellow in color with approximately 50 or so made. They were made by the Allmand Brothers Inc. of Holdridge, Nebraska. They are hillside self leveling tractors.If anyone has any info or corrections please tell us. I have some photos but am unable to show because " the board attachment quota has been reached" sorry.