I photographed these Tractor Tugs at various museums and airport events.
In addition to Clark examples, there are other possibilities like Harlan and Tug
Tractor Tug, unidentified
Erickson Collection; Madras 2023
Tractor Tug, unidentified
While searching to identify this type, I found a pic taken at a Canadian museum that seems to match. Key elements that differ from a Clarktor are the large rear fender.