I'm in the same situation. Just bought a used S240 and went to Home depot and got the BUC10284 Twin bagger, easy peasey right? Nope! It doesn't fit. I called JD support, gave them my SN and they gave me the BUC10284 part number. Then after being put on hold to do more research, they tell me it is the BUC10907 number. Why is it some of the S240 have this oddball obsolete deck? My tractor is a 2020 model.