Correct, but in its condition ( rough ) and having a 18 hp air cleaner and the sticker is not readable , so i was hoping of a metal tag or numbers on it to tell 4 sure what it is ,that i have not found.
No oil cooler or accelerator pump on the carb, so it is an 18 or 20, most likely. The only difference that I could find between those two is the thottle stop screw on the carb if it is an 18. Remove that and it is 20.
The power steering is run off the charge pump on the hydro unit, so same oil. There is basically no volume of oil in it to drain in the steering sector. Change the trans oil, clean out the inside of the transaxle, change the filter, and it should be fine.