This is a picture of my youngest son sitting on a JD 400 Lawn and Garden tractor with a 35A tiller.  We had the tractor in 1977 and my oldest son when he was 12 years old in 1978, would till gardens in town here. He tilled up to 30 gardens a year up until he left for college.  The tractor had a 19.9 HP two-cylinder Kohler engine.  The PTO was in front of the engine and was a 2 V-belt drive.  The transmission was a Sunstrand hydrostatic shaft driven from the engine.  The tiller was a 35A  with a tilling width of 48”.  This setup was somewhat expensive in that day, because you had to buy the 3 pt hitch on the tractor and also the PTO attachment, which you can see on the picture, which is under the tractor, going up to the front PTO clutch.