Thank you for your kind replies.
I am still working on the Roland, albeit slowly, as the Lozenge decals still keep fighting me. I have a tough time fixing the rib tape decals, as the stubbornly refuse to sit where i want them to. This problem is very evident at every trailing edge.
Anyway, you can see some of my progress. As i said earlier, i try to represent Kissenberth's black Roland, but i am using a rather unconventional approach. Instead of "the easy way", painting the fuselage and everything else black and then starting to weather everything, i try to paint the aircraft as it was, i mean, wooden fuselage first, then a rather thin and worn black finish. You can see that i have started to apply the JaSta 23b markings and Lozenge decals on the tires. I do not have to me too cautious with the decals, as the black finish will hide a lot

As there is no known foto of the aircraft's right side, as Greg van Wyngarden confirmed for me, i can use some artistic licence there. The right tire will have no leather cover for the valve (just to show off the interior details a bit). The Edelweiss decal is applied directly onto the wooden fuselage, as this was not painted on top of the black colour, which is evident from the foto in WNW's instructions.
The top picture shows one of my other problems (and the excellent quality of Cartograph's decal set): After drying, a cat's hair appeared under the top wing's Tarnstoff. Big problem, but i decided to live with that as a reminder instead of redoing the whole top wing.
As if i needed a reminder on my cat that usually looks like this:

So long,
Stefan