This is a great machine. Yes, newer tractors have tighter turning radius, and the decks could have been made of heavier material, but the tractor itself is built like a tank.
The old Kohler engine is one of the greats. They don't make them like this any more, and it's a wonder that they ever did. Any of these tractors would be a worthy project for any restorer.
Date of purchase is a guesstimate. My Dad bought the tractor. I was with him, but not sure exactly when.