Here is it assembled..

I found a pretty 23/32" 10 ply sanded pine plywood with poplar core and exterior / high humidity glue for $33.00 a sheet and 5 of those sheets followed me home today.
Here is the plywood with holes contersunk for allow for the trailer bolts..

Then after getting those drilled I wanted to see what the plans for the Generic Ben Roy looked like drawn out so I measured everything out and drew all my lines on what will end up being the underside of the camper floor. I like the results and since I was going to coat this side to protect it nobody will see my mistakes.
Not sure you can see all the lines but they are there. Somethings about the different radiuses make more sense now.

Then I got 2 coats of just regular house paint on it and now it is sitting over night waiting for me to pickup a roll of butyl tape to put down on the top inside edge of the trailer to stop moisture intrusion after the build is complete.

More to come soon. I have ordered my door and galley hinges and I am working on the layout of the galley.