Yea I got the part number from the body of the mower, the only reason I I thought maybe the wrong belt is because I got it from a belts and bearings store, not a Greenfields dealership. The other reason is after some googling I remember coming across a thread were someone mentioned it required a A100, but there are a number of models so this might not be correct.

I probably should mention Ive been a HD diesel mechanic for the past 20 years so I know my way round a spanner, but know diddly about mowers. The Greenfields seem pretty basic in design though which helps.

The deck mount bracket is different to what you picture SuperD, there is no arched bar and no slotted holes. Its basically a mount for the pulley wheels which is bolted down to the deck with 4 x 10mm bolts, I loosened theses 4 bolts hoping it was slotted underneath but nope. I also loosened both the idler pulley's to see wether they were slotted but nope, only the left side has 3 spots where you can move it forward or backward but the distance is probably only 20mm overall but I need to remove a lot more slack than that with the new belt as its already in the centre hole.
Off the back of the deck bracket is an arm that basically sits inside a slot in another section of rear frame, to me it looks kind of like a guide arm that keeps the rear of the deck from swinging side to side but lets it move up and down, sort of like a swing arm I suppose.
I can't see any springs attached to any part of the deck mount. Theres every possibility that this mower has been modified, but Im not sure.

Ok Ill have a crack at posting pics..

Hmmm, not having any luck there. Ive resized my images to 800x600 (120kb) and followed the image upload directions but they don't seem to be loading in. Little bit different to the other forums Im used to, and Im a mod on one of them haha. Sorry Im sure its been done to death but any advice would be appreciated.

Cheers, Charlie