I used to own one,but mine had a 7-1/4 HP Wisconsin mounted sideways with a belt driven Peerless transaxle,not like the one pictured here that had a bellhousing and a "real" clutch like a car...I have seen two just like yours in the past year or two for sale,both pretty rough shape,but they had a live PTO sticking out of the back,and a 5 speed tranny with high and low range..one had a 10 HP Wisconsin,the other had an old cast iron HH Tecumseh or Lauson engine and looked original,so I guess they came both ways..
My Bush Hog was a very rugged beast even though it wasn't the "better" style with the hi-lo tranny and PTO..I used mine to push the dirt I excavated from my garage foundation back up against the walls after they were poured,both inside and outside !..it saved me weeks of hand labor..it had the ruggedest plow & push frame I've ever seen on any garden tractor..low gear was a creeper,there wasn't much it would not pull or push in low!..