Did you try to order one through the CIH dealer?????
Since you did not post the model # of the rotary cutter, we can"t look it up on the consumer CIH parts site, but going by the size, and searching by "part specs" on the DEERE site:
Diameter 1.125 IN
Thickness 0.999 IN
Across Flats 1.688 IN
See Sketch 0.625 IN
Slot Width 0.285 IN
It"ll cost you about eight bucks if you get them to order it on a stock order so they don"t stick you with the freight.