I'll pass the links on to him, thx.  There isn't too much large-scale grain/corn/bean farming around here, but there are a few places that sell used tractor/combine/equipment parts.  If really old combines have shaft monitors then there's a better chance of him being able to look at one with a drive of a few hours.  FarmerTom on here has some used farm equipment parts for sale.  Every time I seem to be able to get there though he's closed and has a bunch of Beware of Dog signs around to discourage off-hours browsing.

 That harvester is for wild lowbush blueberries.  The Oxbo/Korvan harvesters are for highbush blueberries.  Wild blueberry plants grow like a grass carpet and usually only grow 4-10 inches high.  The harvester head is a rotating drum with 16 picker bars that rotate in the same direction as wheel travel.  There is a conveyor belt in the head that carries the berries out of the head and drops them onto another conveyor that carries them to a platform on the back of the tractor where the leaves/grass are blown off and dumped into boxes.  Average picking height varies from 1-6 inches from ground level.  The pickerhead is side-mounted on the tractor and is run hydraulically.  There's a rotating brush (like a streetsweeper brush) on top of the head to sweep out weeds and pulled blueberry plants.