Hi Alistair,
Your LVG is coming along great!
The LVG was my first Wingnut build and second WWI aircraft in general. I remember all too well those wires between the upper wing center and fuselage. I managed to get them installed only to have one pull loose. Somehow I got it reattached though.
Clean is good! I feel that excessive weathering detracts from the model's appearance so tend to keep such effects to a minimum. It's easy to get carried away and end up with an engine that looks like it's been lying in a scrap yard rather than on operational unit lovingly cared for by it's crew chief.
As for turnbuckles, I think they add visual interest to the model, especially in this scale, so usually represent them with hollow tubing. In the case of my LVG I used stainless steel hypodermic tubing as brass tubing of the appropriate size wasn't available at that time. Rigging line was 4lb. test monofilament fishing line painted with Humbrol Metalcote Steel.
Cheers,
Eric