John, after reviewing the service manual I am not sure that the seal housing is pressed on to the main drive shaft or pressed into the transmission housing. The manual is not clear in that regard. I always thought it was pressed on to the main drive shaft. It's been a few years and my head is fuzzy except on replacing the seal in the housing.
Someone who would know for sure is Zach81 as he had a dinged up seal housing in an early 530 that was removed and reinstalled. I was involved in the post but didn't get involved with reinstalling the housing.
Regret that my explanation above may be in error. Would be very interested in a response from someone who knows for sure.
Joe