I have a late's 80's model that is similar. That one looks to be a bit heavier though than mine as it has bigger rear tires/wheels.
As for the deck, check your local craiglslist, these things get parted on a regular basis. I know of a local guy that probably has 3-4 decks that would fit that tractor. You shoudl have very little trouble finding a deck to work.
if you want, I can try to snap a few pics of mine tonight ( if I can remember) and post them of the deck so you can see what you are looking for. Granted, it's on the tractor in a dark barn, but maybe able to give you an idea of mounting and idea as to what it looks like.
I know mine is pain in the rear to get level. It has two trailing arms that mount it in front to the frame, they adjust the front to back position and then 2 fixed lift arms. I have a bear of a time getting teh rear of the deck level side to side, ended up being one of the lift arms up on the one side.
Check the frame where the front axle pocket sits. I had to have mine plated/welded on both sides as it cracked the frame right in the pocket area.