Just wanted to update everybody - thank you for your advice. The subs are now out of the bags. It was such an amateur bs job that was done. The subs were scabbed to plywood that was drywall-screwed through the exterior of the saddlebag into the wood. Then the holes that were drilled so the sound could come through let tons of water in the bags when I rode through a small shower. The bags are likely going to be about 20lbs lighter now that the subs and the water have been removed.
In order to waterproof the bags, I'm experimenting with a couple of approaches. One, I'm thinking of taping the outside of the bags, laying the bags so that the taped side of the holes are against the workbench and pouring Oatey Black ABS cement into the holes and allowing it to cure. I've read about many folks repairing ABS plastic with an ABS slurry and/or cement.
The other approach is to use an Oatey epoxy fix-it stick and just stuff the holes with the putty and allow it to harden.
Thanks again for the advice fellas, it's much appreciated.
-Tim