Mathew spotted this.  Available for sale in Monroe Center, Il, this unusual piece of Willys history is something I’d never seen.  After some research, I discovered another one of these that sold for $4000 a couple years ago, though it was powered by a ford 2.3 liter engine.

“The sprayer was mfg in michigan byRotomist has not been used in several years. Model #100E Is equiped with a willys Jeep engine 4 cyl.  THE UNIT SHOULD RUN AS EVERYTHING IS THERE ONTHE MOT0R PRICE IS 1250.00 PH 815-716-0224”

http://milwaukee.craigslist.org/grd/1881363790.html