I have had excellent success with Gorilla glue. It is moisture activated, and foams to get into each nock and cranny. You MUST hold the piece being reattached in place with a clamp or a piece of tape, as the foaming action will lift it out of its seat. It cures to a light brown color and can be sanded off to match your repair. Curing time is about a hour, but I always leave it overnight just to make sure.
What Joe90t said. "Hot Stuff" is a brand name (basically known to guys who built model airplanes.) but there are many brands of cyanoacrylate. If the pieces are separated, use the "thick" CA. Be very,very careful not to get any on the finish. If it's a crack in the wood, you can sometime use the "thin" CA and let it bleed down into the crack. It works by capillary action, the same way a tree gets nourishment when it's growing. Though it works best with very porous wood like balsa, it will also work with walnut and other hardwood.
I use Hot Stuff (CA) for small repairs like chips. I have used Gorilla glue and yes you have to tape/clamp because the glue expands - I have always had to scrape/sand after drying because I always want the bond to be dry.
I like most epoxy solutions EXCEPT for very small jobs as it is difficult to get equal amounts of resin and hardener unless you mix way too much.
If you repair cracks around inletting, it 'depends'....
I vasilate between Accraglas and Titebond, but if you don't want to get into issues of cleaning epoxy off the finish, or the potential damage to the finish from cyanoacrylate, use the Titebond. Very user friendly.
I sent you a PM. Also get at a med store drug store these rubber hoses, rubber strips. The reason is if you still decide to do it yourself you will need those to hold the crack shut. They will do a good job without damaging the wood. use tape to hold the raping together over night.
The key to it is to fill ALL the crack with the glue. Leave no bubbles or you will be sorry.