help on satoh s650g early fluids question

[okctractorman]

Ok guys im new to this so hears the deal i thought my satoh was late i have done some research and discovered it was early model the clutch works fine the pto does not spin fast enough for nothing and i can stop it by hand the pedal on the right side when i pushed down it stuck down been putting penatrating oil on it 5 times a day it is getting free slowly but im confused what type of oil to use where to use the oil plug by the gear shifter i cant see any thing in it i see gears but no fluid the oil the 3 point lifts fine the oil plug behind seat shows full of fluid but when i first got the tractor i had to remove trans gear shifter and free up shafts it would not go into any gear and goes in gear and drives fine do i have a dry trans not letting pto ingage and what type of oil
goes in trans 80w/90? thanks bob