I just had an organ bellows for a cylinder musical box redone in
kangaroo skin.  It was oil-tanned, not acid tanned.  It's strong,
supple and is now working _great_ with no "break-in" period!
It's more expensive to do it in kangaroo, but worth it.

Nancy Fratti - Nancy Fratti Music Boxes
Canastota, New York, USA
http://www.nancyfrattimusicboxes.com/