Not sure where you are located, but those blowers that are sold at farm sales in the Midwest, are sold in antique shops in California, and they aren’t cheap. I made a blower years ago from a large hand cranked gear reduction grinding wheel. It must have a gearbox, and should not be the little one that are seen most often. These are usually cheap, even in California. I bolted it to a snail drum blower, and added a barbell weight where the original crank was for a flywheel. I also converted it to be run from a foot pedal, instead of a hand crank. Having both hands free is very hand at times.
Hungry Horse