Well it's out... finally. Heat & elbow grease took care of the bolts holding the bracket to the transmission, more heat finally made the hydraulic fitting decide to release its grip.
To repair, or replace? That is the question.
There's a small amount of surface rust at the end of the bore, but nothing that I imagine wouldn't disappear with a little bit of steel wool. I haven't a good idea yet what the rest of the bore looks like--I've only inspected it by shoving the piston back with a screwdriver instead of removing it.
Any suggestions? Success/failure stories? The easy way is certainly to just buy a new one, but the easy way isn't always the fun way.