Lacking PE set for this airplane, or, to better put it, I have one set for 4 models, I decided to copy at least some parts of it.
Here is process of copying the seat (pics 1-3): PE set is attached with tape to aluminium cover of Nescafe can. It was outlined using sewing needle and cut with sharp #11. Best way is to cut it on a hard pad, like glass of plexi. Further it is handled like usual PE would be.
Next thing was to set lozenge on the interior surface of the cockpit (other pics) - for that I used 4-col Roden's decal, since Albatros built Fokker fuselages were covered in this, while wings were, as mentioned before, 5-colour. Decals are fragile, out of register and generally speaking bad, but once set in place (using enormous amount of solvent solution) and overpainted, look quite OK.
To simulate back-side of the cloth, I shaded it it light gray. The same goes for the cockpit back wall, which was also used as seat support, and was also made from Nescafe alu. To apply lozenge, I've transferred it first onto masking tape, which was later fixed to the plate.
Tomorrow I'll deal with engines and other interior parts...