I just picked up this Composter attachment for my early '70s Montgomery Ward tractors. They also built these for AC 300 and 400 Series tractors but the hitches were different. Has anyone used one of these? What do you think of how they perform? Are they fairly uncommon? What are they worth...

Just acquired what I believe to be a 1974 16 HP Montgomery Ward Variable Speed garden tractor made by Gilson. It came with a 42" Rear Discharge Deck, Composter Attachment, and a Sleeve Hitch. Tractor GIL 33154B, Composter GIL 33112. Has anyone used a composter like this before? What is it...