This is one of those toughies!
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Little red circles around possible visible eyes. Further washing would help you out here and don't forget the value of a squirt bottle for tight spaces while dividing.
Try to trace which tuber best belongs to those eyes- might be two at a 90 degree angle; cut them both as one entity and store awkwardly that way.

Far right circle might go with # 2
Middle circle might go with #3
Hope that the far left circle goes with # 4 because #1 looks like a real tough customer.

If you trim the obvious/good tubers first, you might have a better visual of where you can separate some of those big stems. Often, multi stemmed plants will just sort of separate themselves once you get a few tubers untangled. Sometimes you just need to bite the bullet and get out a chisel and HACK. Try trimming the big stems off and chisel down the middle of those stem stubs. Haven't had to do that yet, but I have many clumps to go yet. Some are just monsters, even in only one season of growing.

Good luck!

Thanks Poochella, I was tempted to just wrap it up and wait until spring. (Then probably stick it in the ground without trying. But nothing ventured, nothing gained, right!!