The most successful crack repair I have ever attempted was done with Titebond II. The wrist was badly cracked longitudinally. The crack is no longer visible and has held strong for some 8-9 years now.
Before:
That crack is now no longer visible after gluing and a light sanded in refinish of the affected area. I bought the stock in the damaged condition from Bazil Slaughter to replace a target buttstock that came on my FAIR Verona LX692 28/410 combo.