Looks like a tube frame shredder. Super clean!! Ask if he has the bracket that mounts under the tractor near the foot rests that the point on the end of the frame sits in. Also on the front right side of the frame there should be a bracket that rests in those 2 round spring holes, ask if he has that.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42228&item=4336226270&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=42228&item=4336226270&rd=1