Okay, I've always wondered ever since I read this in 1986: can you really pull a whole face off with your fingers? Also, if he dug in his hands hard enough, wouldn't the fact that it's flesh be apparent pretty quick, like with the first sight of blood? I realize they're supposedly being restrained here(which is a little fucked up, given how far they're already going here), but just one puncture of the skin would have been enough to do that.
It's a pretty clumsy ending, but this is just Grand Guignol, no more. I wonder how much of a subconscious influence this later had on Tobe Hooper.
That said--with all that, you almost don't notice how openly sexual they managed to get in this story, at least for the 50s. (and NICE BOD on the crone, almost Wally Wood-ish)