Now that it's starting to warm up in my garage, I'm about ready to tackle this. I figure I'll clean things up first and see how it goes. Are there any special tools needed for this operation?
Take a scotch brite cookie to the steel plates and add a dished plate to the stack, installed the opposite way that the one that's already in there, and the groan will stop.
Your local shop probably has a used clutch pack that will have a usable dished plate.