Slightly less WIP:
I've done the wings and the tail surfaces, and the general shape of the fuselage. I still need to do quite a bit though.
[Edit] I've done most of the structure at this point.
I still need to do the landing gear, the propeller, engine exhaust, and then detail the cockpit. I might put in some windows to make it the passenger version.
The engine itself is done, but it needs reworking. I noticed a few minutes ago that the drawings I was basing my measurements off were slightly off, in that the engine and cowling appeared as one size in the plan view, and another in the elevations. Looking at some photos, it turned out I chose the wrong one.