Snapped Exterior Mirror (ouch)

This was a self inflicted wound by yours truly (Hit it from underneath with my noggin). I want to proceed with caution and not just jump right in with my 'Fix'. Ive read Shamille's previous thread, lots of good stuff and I think the attachment is similar although the mirrors are different, mine is a NA 1990.

My theory is that the stalk is attached to the base by a bolt that goes through the base and tension spring (to allow fore aft movement IE folding in) and threads into a expansion sleeve mounted in the stalk. If so, its an easy fix once you drill out the expansion sleeve in the mirror stalk. Replace expansion sleeve, bolt and possibly a nut on the other side?



I have ZERO clue on where to find these specialty compression sleeves. Advice/conformation would be greatly appreciated.