"Sounds like You will have to
"Sounds like You will have to replace the crosses in the joint, at least if the propane torch has grilled the rubber seals for the cross needles!
The main reason for your troubles and problems is lack of maintance!
If You are winter storing your boat for a longer periode the best is to take the drive cmpletely off and store it seperately, check and replace the bellows and water hose, lubricate the flywheel housing bearing, lubricate the splines shaft and drive pivot bolts at assembly.
The drive should be removed immedeately after the boat is out of water for the season, not when you want to use it again, and gear oil checked/changed.
There are two ways the water can enter the bellow: Leakage from outside (bellow dammaged or not sealing properly), or from the flywheel housing, through the bearings in the housing and into the bellow.
As for parts: The bearings are std SKF/Timken and probably awailable at any shop selling bearings. Brands and make not important here. The seals You need to get from a Penta dealer or maybe Sierra."