Once the ribs were filled in as much as I could with scrap wood, I switched to epoxy putty, Aves Apoxie Sculpt to be precise.  I used this at the extreme bow where shaping is crucial.  Apoxie Sculpt sands a lot like resin once set up, but a little more dense.  It sands well, takes an edge like crazy (I’m convinced you could make a knife blade with this stuff and get it razor sharp), and is great for shaping and detailing.  Once that was done, it was on to the wood putty.

I took delivery of styrene over the weekend, all the way down to .005″.  Not much thicker than paper.  It’s going to be fun figuring out what type of adhesive to attach this stuff with!