CP-
I had thought about your concept of turning a foam block... especially since the majority of the fuse is round. I love the looks of balsa stringers and am tossing around the idea of using transparent orange monokote so everything is visible = always a cool look. Wish I knew more about tissue / dope covering which could probably lead to a very similar transparent orange appearance as well and be just as light, if not lighter. Guessing this is adding thinner to the orange dope or similar.
In terms of building sequence, thinking of using the concept of building a half of the fuse at one time, i.e. bulkheads cut in half and then install the balsa stringers. Final step would be to attach the fuse halves to make the final fuselage.
Still need to work out how to install the horizontal on the vertical tail so that it remains strong... it is very thin in that area.
Brian