Anyone seen one of these? When I was a kid dad had an old Gleaner F combine with with a swamp cooler on top of the cab. I only remember that it seemed to work pretty good compared to being in the 100 degree heat - although I'm sure it was poor substitute for a real AC unit. Has anyone seen these for sale in the last 20 or 30 years? As I recall (child memory) this seemed pretty self contained - a couple holes cut through the cab top and a power source for the fan. I have one cabbed tractor I'd love to put one on as the AC unit was ripped out by the roots but the green house effect of the cab lives on.