High Julian, photos won't help much without removing the deck, near impossible to see in there. Not knowing what the setup is with the Tractor deck all I can say is that if you mounted the idler pulley square to the pulley deck (discharge chute outlet I think is probably square to the chassis)
and sit the pulley bracket in 70mm from the rear of the deck you would be in the right area. Sticking with the Tractor might be a better option and don't let the steering fool you the Anniversary one is no better, they are pretty bad as well. The Evolution steering is a better design
