It is a JD 110 round-fender. Middle '60's, and the early Deere lawn tractor. They are a collector because of the round fender.
The very beginning production had 7 hp Kohler, and around '64 Deere put in the 8 hp Kohler. The one you show is a bit beat up, but likely worth restoring. Appears the starter-generator is missing, and a rope is used to start it. Mfg. in Horicon, WI at the Deere plant there.