Thanks. This technique also allows partially translucent flying surfaces. I think it could be useful on SPAD fighters but it would require to scratch re-build the entire wings...
The cockpit has been detailed with plastic bits around the original EE parts. A wall has been added behind the seat and the floor was cut so the bottom of the fuselage and control cables are visible like on the real machine. Arrows point to small platic pieces used to align the fuselage halves:

Before the fuselage is closed. Instruments are slices of plastic rod with home printed instruments.

After gluing the fuselage halves, I added the lower wing. I then added the caps on top of the cowling and the hook on which are attached the cabane wires. The joints between tail planes and the fuselage have been smoothed with Milliput.

Cockpit view. Holes were drilled to let the aileron control rods go through:

The bird is now ready for painting. The undercoats roughly match materials, the wooden parts being simply painted acrylic brown. The red paint should leave various shades and possibly the lozenges, see through. Arrows show the opened airscoops and the elevator horns.

Since the last shot, I've masked the lower wings and cockpit aperture.