I don't know what the original poster will do, but I am certainly interested in all the suggestions.
I have recently repaired three different stocks with cracks in them. With two I used epoxy and the other was better adapted to good old fashioned white carpenters glue. Would have been crazy glue, but didn't think the surfaces were quite right.
In all cases I found the best way for clamping was with big rubber bands around the stock. Much better than trying to use a mechanical clamp, but will only work in certain cases, of course. Wouldn't work on a crack from the butt up.
Once used gorilla glue for metal to metal, improvising an aperature sight. Wow. Huntinstuff has sure got it right on amounts! It has tremendous strength,though. Only problem was I used a very small amount from quite a large container. Sealed it up best I could, but next time I looked at it, the container had swollen and it was hard as a rock. Will get the smallest amount I can, next time.
Every time I look at a good display of glue, there is something new. Some new products sound very good.