Alan the natural resins in Coco react with just about any oil used on it, at least any type of oil that coats. I have been told by oldtimers (not guitar related) that have finished it that it will never let an oil finish dry. Will remain, stickey to the touch.
I know when I first tried finishing it the piece of coco was on the fore end of a rifle stock. I had to let the wood age to get new bright colors back after the final shaping and sanding. All the new color.....resins! I shot it with lacquer and those new colors bled into my nice new stock!
I had already been informed not use oil, but no one told me about bleeding colors!I think if you will strip to raw wood, and then wipe lacquer thinner or acetone, you will be able to coat the coco with shellac and then finish normally. That is a guess though.
Mike