Two stage planetary gears! Thrust bearings! That motor is quite different than any I have seen before. Venturing into the unknown. Great job on coaxing it apart.
There are two extra bolt points on the motor with nothing in them. You use the bolts taken out in these points to push the motor open. It also has a line marked on the casing to keep it square
You disassembled the wrong part. The clutch is in the part you put aside. It's between the ring gear and the side cover. Most likely, the rollers have stuck due to rust or lack of use.
