I actually bought a seat from Tractor supply and ground the studs off of the seat pan. I removed the torn upholstery and cushion from my original seat pan, but I left the original seat pan mounted to the tractor. I untied the string holding the vinyl cover on the tractor supply seat, pulled the vinyl back, and set the complete tractor seat in my original pan. I pulled the vinyl over my original pan and retied the string. It works great and I didn't have to modify anything on the tractor. Eventually I'll get around to doing a proper reupholstry job on my original seat.
I'm going to look for that seat, that's a GREAT idea.