They seem to be very hard to come by.....I've been looking for 1 or 2 myself. The good thing is the front hitch is essentially the same for the 5000 and 6000 series, despite different model #'s. The angling kit is just 2 cylinders that replace the solid metal bars, a generic replacement should be feasible.
Let me know if you find a few tucked away in a dealers warehouse!