I have seen a ton of old Gravely attachments but I have never seen this before. I'm trying to imagine what on earth you would use this for. http://columbus.craigslist.org/clt/4152131926.html
Holy Cow!! Can you imagine that ting coming at you? With the sitting seat installed? I could cut a path real quick
I think the reason they are so rare is obvious. It's as useful as a one legged man at an arse kicking competition.