RE: Benz Bz IV - 1/6 scale engine scratch build
Flying Fox:
Will be quite an undertaking to say the least, but well worth the effort. That's one thing with the German aircraft with those straight six engines, you have to model that too or it just won't look right. Build it on the heavy side because you will need the nose weight, take it from experience, Pfalz D-XII, D-IIIa, Halberstadt DV, Albatros D-Va, Fokker D-VII.
If you are in need of plans for a really scaled out LVG CVI, I have a perfect set of them I'll sell you, just leave a post or PM.
Dan