[bigeasy1]

Hmmm,Gee,that's a tough one.What did you glue it in place with? Do you really want to rip the hole thing out again? I shiver even thinking about it.

Just some random thoughts on my part,not really sure what i would do.
Is the space open all the way to the end of the wood,where it meets the side of the hull?Maybe you can work some thickened putty in between the space.
Have you thought about possibly cutting that 8" piece from top to bottom out,and replacing it,along with fresh adhesive.You could build up the inner glass a bit thicker over that area.

Pouring resin in between won't give you much strength,You might be better off mixing up some resin with some milled fiber,for strength,and a thickener like cabosil,and try to push it down between the core and transom,with a long pice of wood os something similar.
What about that pourable transom repair stuff,i forget the name,(is it transom pour?)that might fill the bill.

Keep us posted on the progress,and give us some pictures.Good luck with the fix.