with the way you are talking it sounds like they were wet tanned? That will shrivel and turn hard. You are going to have to break those skins. Get a big two by four and start moving it back and forth over the beam to break the fibers of that tan.
If they were soft tanned I would bring them back to the tannery, No way a soft tan should be doing that, I have a caribou that was tanned back in 1993 and it still hangs on the wall.
Joe