I hesitate to post this for fear of getting your hopes up.
A neighbor of mine says that he will be hauling off some old Grasshopper components due to a friend of his moving away. He has said that I can have whatever I find in that junk pile. He said there was a deck, but has no idea what size it is. IF he comes back with a deck and IF it's a 72", and it has the parts you need, you are welcome to them. I have already donated a few parts to another member.
Like I say, don't get your hopes up, but there's a long shot that I might get what you need.
Larry