I tried to find this on the forums, but I couldn't find the thread I remember reading....maybe someone else can dig it up, or maybe I just imagined reading it.
Dredging my memory, however, I remember someone saying that the Dumbo spinners will oppose each other -- one will go clockwise and the other will go counter-clockwise. Furthermore, I remember saying all Dumbos in the Disney themeparks go in the same direction, so this will be the first time that individual Dumbos will have to be manufactured in reverse (bolted to the spinner on the other side). So, to the OP's original question, it would be a maximum of 50% recycling, since the other spinner would require mirror-image Dumbos.