I just repaired the wrist of my '97 Winchester. It is black walnut, and has a lot of oil soak, being a Winchester, and likely stood on it's butt for the last 100 or so years. I shaved off the top of the wrist to a flat plane, made a piece to replace the missing wood, and drilled 1/16" holes down into the old wood to form a matrix of anchors. I mixed up some AcraGlas from Brownell's stained it black, and laid it on. I clamped the wood first with tape to orient it and then with rubber bands to add pressure. After it cured, I finished it up, and shot it on Sunday and again last night. It seems to be holding up fine, but time will definitely tell.
Having already tried Gorilla glue, I think you're euchred. Anytime a glue line lets go, it is next to impossible to re-glue it with success. It may be necessary to completely break the wood apart, and mechanically remove the urathane expanding Gorilla glue. I've fixed some stocks that were smashed to pieces using Acra Glas,,,great epoxy. But on raw wood, Titebond III is wonderful.