Thanks for your input. No, his paw doesn't go into his mouth, just the bed. When he finally lets go, it's soaked! But he doesn't seem to be chewing, just "grasping" if that makes sense, lol.
It is cute, but in an odd way its a little heartbreaking too. He seems to get comfort from doing it, and (he was doing that when I posted earlier) after about 10 minutes he lets go, repositions himself and sleeeeeeps.
He's the only dog I've ever had who sleeps so deeply, we have to physically pick him up to wake him.