Aw bummer...an "opportunity"...question...hard to tell in the picture, have you installed the rails yet?  Also, will you be painting or varnishing the inside?   The outside?   

   The first layer of the rails is on. I'll be painting the outside, but not the interior. 

   Your plan should work just fine. No need to take the entire transom fillet out, just enough to allow you to get some thickned epoxy behind it and pull it in tight with wire or clamps. I fixed a similar break on a Passagemaker by loosely wiring the panel, leaving enough gap to get thickened epoxy in the entire rabbet, then pulling all the wires tight causing the excess epoxy to squeeze out. Wipe up all the excess and 24 hours later your boat will be back to normal. Just check the other joints to make sure there aren't any other cracked panels and if there are force some epoxy in them. When you're done nobody but you will know anything ever happened!

George K

   second what George said. My dad and I broke off the last 6 inches of the bottom panel of the first WD12 we built. A little bit of epoxy and glass and it was as good as new. We learned alot on that boat. Good luck. JRC

   Thanks, George, JRC...I'll be working on it later today! 

   Looks like an easy fix, I call it a PITA but your plan is a good one work it.

PITA= pain in the anus

Bruce

It was a PITA, but thankfully relatively simple to fix. She's all squared away upside down(once again) so I can finish the bottom. I'll be sanding(and sanding and sanding) then glassing the bottom and onwards to epoxy, primer, and paint! With, of course, much sanding inbetween ;)

~Jennifer