I do not have the magic undo button for you. But I will say some of the ideas given are good. Tite Bond III would be a great glue to use as all ready stated. It's slow drying and that is what you want. Looking at picture 216 I would only glue the area back to the first pin, as not to get a lot of glue in that pocket. Because it will need to be cleaned up after taking barrel out. As stated carefully pry apart wide several times letting glue have a chance to really squash in and soak into the wood. Have the barrel ready with release agent, or something like wax paper from the kitchen (if it is thin enough). Do not come back saying you can't get the barrel out. Have a way all ready figure out of how to clamp or wrap tight that area. Think it out and make a onetime fix. Be sure and remove anything that might get glued in place beforehand. And then let it sit at least 24-48 hrs. Thats right no hair dryer to speed things up.