Scott: I'm not even remotely tempted to try fixing this myself! I know a gunsmith that teaches a gunsmith course at our local community college. He's done some work on my father in-law's rifle before; and if we let him use the recalcitrant shotgun in the classroom for instruction purposes, he won't charge for the repair. I'll get it to him, and when it's done, I'll post here in this thread about what happens.
Seen on a bumper sticker: "Exercise. Eat right. Take vitamins. Die anyway."