If I were you, Tanaka-san, I would summarize like follows though I do not deny your good job. No problem but technical explanation looks a little weak when questioned by a technical expert.
Main points to identify the relic.
1. It is not a generator but a motor because of its structure.
2. There are two bolts on the relic to fix the motor to the base.
Therefore, it is neither APU generator nor a motor for the turrets.
It is a motor for the hydraulic system as the design and purpose coincides to EE125M1 well as example.
No such motors are found in the B-29 except the motor for the propeller feathering pump.
Therefore it is natural to think that the relic is a motor for the propeller feathering pump.