Have no idea of how you can remove it without damage so lets discuss attacking this from a different angle. Since there is little to the tailshaft housing other than the housing, bushing and seal is there anything wrong or it it too worn on either the bushing or seal? If not I think an evapo rust soak, a good rinse and dry would work. Not sure how your treating the main case but you will need to match that final look but if your creative I think that will be doable also.