Thanks for your reply. 1cm was just a guess (it may not be that big of a crack, but the crack does appear to be into the wood). I have added a picture of the crack. Thanks.
If you are going to sell it..... do not try to fix it.... it is worth more as it is............ someone will see it;s value even if it is less than perfect.....
If you are going to use it as a player......... fill the crack with black epoxy.
Kim