That is very cool it's amazing it is still could be found. 

Question I saved a 9u d6 with a blade from going to scrap. It all complete with pony motor and it runs and drives. The problem it must have a stuck ring or broken ring it runs oil out the exhaust. I have not run it a lot but will run it some more after harvest to see if it clears up. Can you still get pistons and rings? Any suggestions on what else to try. 
I worked for Stone machinery as a young kid they were also a Massey Ferguson dealer back in the day.