Patrick,
I just started my Triplane build and have been studying your fine build along with the several others here looking for hints, ideas, and trying to ensure I learn from the experience of you Guys who have done this one before me. I have a suggestion and some thoughts regarding the cord wrapping on your control stick; just my suggestions...........
First, you've mentioned several times that you are not happy with this part of your Build and, to repeat a very wise bit of advice from "Bo" on this Forum concerning another Build here, maybe consider changing it as it is bothering you and, importantly, "you know it's there". I've gone through the Albatros Publications Data File #22 as I was considering trying to replicate the cord wrap (not an easy job methinks!) and most of the photos of the cockpit show a plain metal hand grip, no cord. The photos I speak of are of the RAF Museums refurbished N5912, there are 3 or 4 very clear close up photos showing the plain metal grip. There's also a very clear photo of the cockpit of N6292, "Lily" of 8 Naval Sqn. taken in July 1917 and again the plain stick grip is very apparent. In fact, the only photos I have of the cord wrapping are on "Replicas", notably the one in the Canadian National Aviation Museum taken in the early 1990's. Based on the foregoing I intend to do the plain grip as I believe that was the normal configuration. At least, in my view, the logic seems valid as I'm doing N533, a twin gunned version like yours and of the same configuration as N5912 of the RAF Museum. (albeit N533 and N5912 were built by different sub-contractors) Remember too that, like colours and markings, there is rarely a definitive answer to any question on these aircraft, it's been almost 100 years since they were in service!
Having said all that I believe you could simply reach into your closed cockpit and snip off just the top grip, replace it with the cleaned up original or a scratch built plain one, and feel much happier with your excellent Build. If you are like me at least you'd be able to sleep better having put it back to where you want it!
Just my thoughts and logic, hope you consider it in the constructive spirit offered; you've got a beautiful Model coming along here!
Cheers,

Lance