Hard to tell from that tiny pic. If it is just missing the shaft.... it would be simple fix... after shelling out for the new pto shaft. If any of the other gears, etc., that drive the output shaft, it could be an involved repair and would be costly piecing it together from Deere. Quick estimate would be about $500 to get the shaft, gear, bearings/seals, etc. from Deere. Double that or more if other parts that drive the PTO output shaft are damaged or missing. Best bet would be to find a parts donor.