Shrinkage is always a problem with wooden grips and depending on the type of wood and the climate it can be quite severe. Almost all of my Commando knives with wooden handles exhibit cracks near either, or both, ends. Today's knifemakers have the luxury of using stabilized woods, which help prevent, but does not always eliminate this problem. I have some very expensive fighting knives that have hilts made from Stabilized burl woods which have still suffered some shrinkage and resultant cracking.
I am also building up a finish of Danish oil to help nourish the dried-out wood. The grip shown above almost looks as if it was used (or abused) in a wet climate, giving it the look of some of my wife's antique kitchen knives. I think three or four coats of the oil will sink in and produce a nice finish and help preserve the wood.
Originally, I was hoping to remove the screw and hilt to inspect the tang construction. That was not to be, as the screw refused to budge even with a wrench applied to the screwdriver shank. I don't know it the screw was loctited by someone, or just way over-tightened, but I did not want to snap the head off.