Thank you for the paint tips Alexis!
The Lozenge should also look Great when applied!
Hopefully

I selected this time a full sheet from my stash with a 45° connection between the stripes. I hope to reduce effort and waste, instead of using the in-scale singe stripes, which I used in other projects.
Will the underwing lozenge on the upper surface be too light? Not sure - just a question.
Stephen, that was one of the reasons to select this marking. The Halberstadt Cl.IV and many late Cl.II has the usual lozenge applied, dark on top and the brighter one below. I know only some early Cl.II with bright linen on lower surface and the bright lozenge on top. In the Ronny Bar profile it looks even a bit more white, bleached, faded. I like that look, may be I put a light layer paint on it.
I don't know, why this was done. I could be a communication problem? May be the factory was told to use lozenge, but at first (and only) the brighter variant arrived, so they simply used it? May be some experts know ... And that is the only type I know with the bright lozenge on top.
Andreas/Borsos has build the "neighbor" with the tactical number 4 on it, same lozenge style, in the Memorial Group Build:
https://forum.ww1aircraftmodels.com/index.php?topic=10173.msg200629#msg200629By the way, what is the correct type? Cl.II or CL.II ? So uppercase or lowercase "L" ? I have seen both in books, WNW used lowercase. May be I should check some Idflieg documents.
Edit: Found some pictures of type plates on aircraft (the manufacturer should know) in WD27:
"Militär-Flugzeug CL.II xxxx/17" xxxx for serial, and
"Halberstädter Flugzeug Werk G.m.b.H.
Halberstadt Typ HalbC.L.II No. xxxx"
Cheers,
Frank