Had a 6hp Wisconsin many moons ago, when I was a kid. Dad found it in a scrap bin at work, complete minus flywheel. I needed something for a demo at school so dad and I cut the engine down the middle of the bore, about 1/4 of the crankcase, and half the head, so that all of the moving parts were visible. They still have it at the school but they had to put it in a case so that the rodents wouldn't smash their little fingers playing with it or drop it and break a foot. That thing was all cast iron as I recall.
Didn't Robin get involved with Wisconsin engines? Robin is now a division of Subaru (part of Fuji Heavy Industries aka FHI which is also partly owned by Toyota), if I remember correctly....who also builds some Polaris engines as I recall. Could be wrong? Seems like I heard the term "Subaru-Robin" thrown around--and I do know I've heard the term Wisconsin-Robin quite a few times in my teens & 20's when I did part time work at a lawn mower shop. The older gentleman I worked for loved messing with those old engines--mostly on garden tillers, or at least that's what I saw them most on.
I do know that Subaru/FHI built the engines in the Kubota RTV400 series, but the 400's have been discontinued (thank goodness)....and Subaru is, as I remember, out of the small engine business now. Seems like 2017 October they sold off their industrial engine stuff.
