I'm tempted to not answer because I haven't built an Eastport Pram but I would think if you lay the parts out like the photo you included the rabbets are all on top on the edge closest to the middle. 

All  the rabbets are cut on the bottom, inside edge of each panel. The panels in the diagram are all  laid out with the inside up. The curves are correct. You'll see it when you start wiring it together. 

George K

Not a stupid question at all.  The curves are very non-intuitive for a first time builder.  I quadruple-checked when building mine.  I even made sure to mark my templates after a successful routing.

Number 3's and 4's get rabbeted on the convex edge.  Number 1's and 2's get rabbeted on the concave edge.  If laid out like the diagram, all edges toward the bottom panel get rabbeted.  

Also, make sure that if you have a "good" side and a "bad" side to the plywood of your choice that the "bad" sides receive the rabbets, leaving the "good" sides long to form the lapstrakes.

Hope this helps.  Truly one of the best projects I have ever done.  Good luck and keep us posted on your project.  Having successfully completed the plans version, I'll share whatever I can to help anyone else out because there were several nights where I worried over a step or a process.

Sorry, got logged out mid-reply.  I posted the above.

Let me rephrase my earlier "good" and "bad" comment.  I should've more accurately stated that the rabbets go on the plywood face that you plan to have on the interior of the boat.