Just a guess, but I think it looks like it has gotten wet, then maybe dried with a too hot heat source - hair dryer, furnace vent, or similar - instead of drying more naturally or stuffed with towels. Maybe it was stored in an area that was not climate controlled, so it went from extreme hot to extreme cold weather? If you determine it to be leather rot/dry rot, it will continue as no amount of conditioning or cement can stop that process. Dunking would accelerate the rot or falling apart condition too. It looks like it will be a constant battle of trying to keep it intact. But.....you know better because you can actually feel the leather.
If it was recently purchased online with inadequate photos and/or undisclosed condition, I'd be very inclined to return it as "NAD". Just my opinion.