Update...
I picked up the Bondic today from CT ($18) and tried to seal the gap.
My first attempt was a bust, I tried to just use it on the seam but it didn't hold. I hooked the stock to the rifle body and then tried to bring it back but it split again. I think the bead was just too small to take the pressure.
My second attempt was to put a few small patches that overlapped the seam by a few mm on either side. I did this on both the top and bottom seams on the stock and it seems to be holding. I hooked the stock and brought back to the normal rifle position and it was holding. I'm planning on using it next weekend for a field skirmish and I'll see how it holds after a field trial
One thing though because of the location I used it, it's right under my nose when I sight down the barrel and this stuff stinks. Hopefully the smell will decrease because it's not pleasant.
I can see it has it's uses so I would throw it in my field repair kit along with a small piece of sand paper to rough up the surfaces.
