Without having seen the project it sounds like planing it to shape would be throwing good money after bad. I'd get on the phone to CLC and get a price on replacement parts. A cheaper option might be to make a pattern from the pieces you have and fabricate your own new pieces, assuming you can get BS 1088 marine grade plywood in the correct thickness. You might even be able to recycle some of the bad plank.

The plank components on my NE Dory all looked confusingly alike at first, and in my kit they had labels. 

Sorry to hear about this. Still, it can only get better, right? 

�Thanks John. Getting it locally may be an option. Thanks for your feedback.

 Of course I would never make sure a stupid error, but there is this guy named Mr Dumass who occasionally comes over and works in my garage.  He glued the side panels of my Ch17LT backwards, so that the bow was facing up and the stern was facing down.  He made a call to CLC and they suggested taking the puzzle joint apart with a heat gun.  Worked like a champ.  The epoxy get soft and the joint easily comes apart with no damage.  Once the peices are aprt, clean off the old epoxy (heat gun/scraper or sanding) and reglue the right way.  My only tip is to be gentle with the heat gun so that you don't burn the wood.  If you are careful, there will be no evidence of the crime.    

���I heard about this but is it possible once the epoxy has cured fully? This would be an awesome solution if possible! Thanks Mark.

   Yep, heating Epoxy with a heat gun and a new exacto knife blade will do the trick. Don't burn it, just get it soft and gently cut it free.

Good luck, and please let us know how it works out, K.