Hi,
Cant help with the tensioner, i would have one on my 24/34 fastcut if you need pics or anything though.
As far as removing wheels go, I am not aware greenfield had a specific tool, never seen one anyway. The main part of removing them is a shock. i have got them off by just loosening the nut, everything just on the ground tyre inflated and hitting the axle with a hammer through a block of wood.
But when i have to remove a really stubborn one, I remove the tyre, then throw a big 3 leg gear puller on the rim, leaving the axle nut on but loose so as not to damage the shaft, then tighten the puller up. once there is weight on it, strike the puller bolt and it should come off. if not, I heat the wheel hub from the back if possible, hard to do on the sprocket side, then tighten and hit again. the key is the the strike to break the taper lock.
