I have tons of ray skins laying around. Depending on how the ray was tanned, they can be super grippy. Though really hard to cut cleanly without a machine. I have some neat ray skin that's been sanded down and polished flat. Still has the look of the skin, but is smooth and thin (more ideal for skinning a camera I suspect, but the polished rays are a bit to small for an M-P, though truth be told I never really checked this out).
Should be awesome, can't wait to see the finished product!!