I use plenty of one year old gas. Not in my saw normally but in gas stuff like mowers and old trucks all the time.
Amazing, I grew up with a 966 Hydro affectionately named "Big Red". It wasn't the biggest tractor on the farm by then but it did a lot of work. The owner considered it his favorite and loved to run it for hay work. That tractor spent a LOT of time hooked to the square balers and bailed hundreds of thousands of bales. Letter series farmalls (3 Hs and 3 Ms, no supers) did all the small work too.
Well the 1066 stands for 106hp 6 cylinder but most of them were closer to 125 go so yeah it is probably 3 times what it takes.