I agree with all of Aaron's comments. You can avoid the interaction with the transmission by putting the clutch in and rotating the hold bracket into position. Rings will seize if water gets into the cylinders from high humidity. When it sits for a long time, the oil will drain off the cylinder walls. If condensation follows, rust can happen. For some reason, Molines were more notorious than others for this problem.
Also, I do not put blankets over machines that are in storage. The blanket seems to increase the likelihood of condensation because the blanket holds down the natural heating and cooling. The blanket will permit greater temperature differences between ambiant and the steel. This promotes condensation. If you are on concrete, I wouldn't cover it at all. If dust, etc is a problem, use a very light weight cover and cover only the top. Let air get to it.