So, after scouring the internet I found this picture, submitted to IH's patent department. It's a 782 with a 63" deck, hubcaps, and a sleeve hitch bracket. The deck is very interesting, the mule drive is super wide at the back. Too bad we never got to see it.
Edit: I guess people wanted better commercial mowing and IH was planning on making a 63" deck for the tregular GTs, but the 982 got a 60" deck instead.