They don't overlap, they butt up against each other, so there's no gap.

It's late here, so I'm signing off for the night, but if the answer is not clear I can try answering it again tomorrow morning.

Laszlo

   Thanks for responding...

Right - that's my question- on the overlap it leaves a space the thickness of the plywood where the deck piece is higher than the stern. Are you suppsed to place the cloth all the way down to the edge and then fill the space with epoxy? Or hold the cloth short just on the top piece?

Just seems weird to place the cloth all the way and fill the area with epoxy and sit the coaming on top. It cretaes an area right under the lip of of the coaming where it's just that area that was filled in with expoxy and on top of the deck (the wood)

If you pulll the coaming forward so it sits on the deck, it then creates about 3/4 of an inch on the back where the spacers and coamng are forward of the back part of the deck

No, you missed my point. Here's another picture that may show it better:

Click on the pictures to enlarge them. Zoom in. You can see that here is no overlap. The front half of the deck does not sit on the back half. The halves butt up against each other.  When they are properly shaped and stitched together the 2 halves match up and sit flat next to each other. It's a more or less flat surface under the coaming. The problem you are worried about does not exist.

If your front half is sitting on top of the back half, you're doing it wrong and need to re-stitch the deck pieces to each other. Have you put the under deck formers in place? They will shape the deck pieces correctly. See the picture below.

   OK - I see what you mean,

So - somehow then I've built my boat wrong as i do have an overlap. When assembing, it all fit and the horns fit well and the bow and stern fit well. Not 

To late now, guess I'll have to glass over the areas and see what i can do to adjust the coaming so it i get a reasonable fit. 

Here are some pics showoing the overlap and how the horns blend 

   OK - I see what you mean,

So - somehow then I've built my boat wrong as i do have an overlap. When assembing, it all fit and the horns fit well and the bow and stern fit well. Not 

To late now, guess I'll have to glass over the areas and see what i can do to adjust the coaming so it i get a reasonable fit. 

Here are some pics showoing the overlap and how the horns blend 

That last picture explains your situation. But, don't worry, it's fixable. First, though, those nibs that are hanging off the sides of the pieces. Those should have been removed before you started stitching. They're an artifact of the CNC process and will interfere with the fit of the panels, snag your glass, etc.So before you do anything else, get rid of them with a rasp, block plane, sanding block or whatever your favorite tool is for that. Be sure you get rid of them from the whole boat.

Now that you've done that, here's what that joint should have looked like:

You can get yours almost the same. The coaming is meant to rest right up against the cockpit opening, so there'll be plenty of room for you to fix the discontinuity. Just sand off the glass hanging over the "cliff", apply a bead of woodflour epoxy and make the thinnest fillet that you can to smoothly transition the "cliff" to the "valley". Brush it with unthickened epoxy to get a smooth fillet that doesn't need sanding. When you're done, most of the joint should still be wood. Do not just cover the whole surface with epoxy/woodflour mix. Treat it like any other fillet and put on some glass to cover the fillet, the entire area under the coaming and run it on up over the front deck for about 2". That will give you maximum strength.

Now do the same thing under the deck to fill the discontinuity there, too. When you've done all this you'll have an excellent foundation for your coaming and the mistake will be invisible to anyone who doesn't know to look for it.

Good luck,

Laszlo

 As I had a scrap piece of sepelle, I scribed and piece for each side and epoxyed the is place feathering the rear area down so it blends in.  I'll now just place the coaming as normal. Looks just fine. Live learn I guess.  Will add a photo when done 
 

thanks for the advice 

Jeff

Yes, please do post a photo. Fixes to problems are always interesting and educational.

Laszlo