Looking at the pics above the upper/fwd pulley is 3in in diameter and of V (not flat) configuration. I can't find a Greenfields v-idler pully of 3in diameter, but there is Toro one that is avaialble.
The lower/centre pully is a flat idler of the same dimensions as the GT1009 of the rear pully pair.
I'm getting to the point of desperation for getting these pulleys off - has anyone else had success in getting them off? Is there some trick to preventing the bolt shafts from turning with the nut?