I made a few minor changes to the design...but I'll show that next time along with the plywood layout.

I ordered four sheets of 6mm Okoume from Edensaw woods http://www.edensaw.com/ which was about the same cost as other sources but I could pick it up in Tacoma without paying $40 a sheet just for transportation.

I ordered a gallon of Raka resin and its 350 hardener. It gets good reviews and easy to mix 2:1 ratio.To start off, I scarfed the plywood together into 2 4'x8'x16' sheets using 10:1 slope. I used a plane to remove most of the wood and finished with a belt sander and flat vibration sheet sander. As you can see the layers make a nice guideline. 
















I mixed up a couple ounces of epoxy, applied it to the feathered ends, let it soak in a few minutes. Next I mixed in some wood flour until it was like thin peanut butter and used a wooden fork put a thin layer on the plywood before joining the scarfs together. I held down each pair with a line of filled water jugs for two days.

What's it going to weigh?

Freeships will get me part of the way. It allows for input of material density and thickness which it combines with developed surface areas to obtain a total weight as in the table below.

 The rest I'll have to do by hand, or using excel, in this case. The cleats will do on top of the bulkheads to strengthen the plywood edge and give a good gluing surface. The support beams will be spruce or pine crosspieces to support the thin seat plywood--I'm going with a beam every 6 inches which is close to Skene's scantlings. Next is I'm going to cover the plywood with thin fiberglass weave two coats of epoxy and another layer just on the bottom with one coat for traction and to strengthen to bottom. According to my original Gougeon brothers Boat Construction a pound of epoxy covers about 35 sq feet, I've got 52 sq feet in the planking. Add long strips of wood for the inner and outer gunwales. I added a pound for the 4 bronze oarlocks I'm going to canalize off one of my rotted hulls.

Add it all up and wow! I'm at 71 pounds. Of course I haven't added the fiberglass tape on the seams, nor breast hooks and paint of course but 75 to 80 pounds looks realistic. Nice. 

Next time I'm going to show the plywood layout.