I am about to re-skin my gone (hare) djembe, and noticed that the hairline crack I saw the last time I re-skinned it has gotten alarmingly more pronounced -

. As this was my first serious djembe, and is signed by Mamady, I don't want it to get worse to the point of ditching it. My questions are:
1. Would you do anything about it?
2. If so, what would you recommend?
The shell has been seasoned with Danish oil (on recommendation by the respected importer from Melbourne), as opposed to my lenke shell which has shea butter. I am happy to sand it back to make the appropriate repairs if necessary

. Some piccys are attached for reference - couldn't attach the one that gives the perspective of the crack on the overall shell, but the tape measure should give you an idea.
HELP!!!
Alifaa