I have found a grader, which I don't know which manufacturer this is, Leeboy (old type) or Babcock. http://s761.photobucket.com/user/mswoodman/media/grader.jpg.html Do you know something and the type??
I have found some photos from older pictures from Leeboy (1995 for example) the graders look a bit different like this. So I think the picture from the link is Babcock.