I have a Martin D-76 that was given when I was about 24 (far before I was responsible/knowledgeable enough to own a guitar of that caliber...). In looking at it recently, I noticed that, among other under-humidification damage, there is a crack in the fretboard that goes vertically (around the star inlay on the 15th fret). Will proper humidification from this point forward help to reverse that damage? If not, what is recommended?

Any help would be appreciated.