You should try and get in touch with the "Friends of HMCS Haida" and see if one of their number is an old underwater weapons tech.
I think that what you have there is one of the actuators for the 21 inch heavy torpedoes that were on the WWII River class and Tribal class Destroyers, which were connected to the gyro system to steer the torp. But I can't get my hands on the old drawings our unit used to have to confirm this. I don't even know if they have the drawings anymore, since they moved out of the facilities on Drummond street years ago.