Hi Zak
Not sure if it says on the instructions for this kit, but on the WNW website it recommends pinning the control surfaces with brass rod. Otherwise the contact patch is to scale, and they are very weak.
I had the same dilemma on turnbuckles. In the end I went for homemade eyelets and a knot sealed with superglue, then touched up with acrylic paint to thicken the end slightly. When I see brass tube on the end of a rigging wire, I think it looks very pretty, and it definitely wins in National competitions, but I felt my approach looked more like the real thing, which was more important to me.
Your build is looking very nice, cracking job sir!
Roger