I cut some strips of balsa at 45° to use as fillets along the fuselage.

There is a bit of a flaw in my design when it comes to waterproofing the interior, it is almost impossible to get under the stringers. There are twp options, one would be to put little walls in, essentially dropping the stringers straight down, and narrowing the "cargo" space. I didn't want to do that, so I used a sponge to squeeze acrylic paint in everywhere that I could. Not ideal, but it's probably ok. I will fix this in the next design.

The decking is going to be done with 1mm veneer. I tried to make a 2mm ply out of it, but it ended up being too rigid to conform to the curves. If I built this again I would just use 3mm balsa, but I was insistent on using the veneer that was kindly given to me.

After pegging it to the stringer I made a rough outline from the bottom, so that I could cut it to shape (with a box cutter).

The gluing process involved lots of weights (to keep the middle down), as well as pegs (to hold the edges to the stringers) and electrical tape (to hold the outside edges down) and zip ties (because I ran out of tape!).

The unwrapped (and trimmed) result is starting to look pretty good, if I say so myself! It looks like something batman would be proud of (once painted black, or very dark gray of course).