Removing Old Glue from Bovine Bone Chess Set

I have a bone chess set (probably bovine - I think they're all bovine?) and one of the pieces has been rather badly repaired, leaving great splodges of excess glue.

I'd like to improve upon the previous restorers efforts prior to sticking this set on eBay. Can anyone here please advise me on how I might soften this old glue without damaging the bone?

The glue looks to be mostly transparent.

Here's what it looks like. At least this is how it would look if you were standing on your head.

You can try a solvent of some sort.  Perhaps vinegar or acetone? 

I think "desolve-it, sticky stuff remover"  works fairly well. It works for removing felts from old pieces without damaging the wood or the felt (although you need to wash the felt well and let it dry afterwards). If it's superglue, Gorilla and Chestnut both sell cyanoacrolate debonder. No idea how any of this works on bone mind you.

😓 Gulp!