Home-made turnbuckles for a 1/32 Nieuport 28. They're made from a 0.2" brass hex nut from RB Motion sandwiched between two short (1mm) lengths of MFH 0.4mmOD tubing. The "rigging wires" are 0.15mm "invisible thread" monofilament. The tubing lightly grips the thread, and needs a thing cyanoacrylate glue to hold it all together before the excess monofilament is trimmed. I hadn't done that when I took the photo'.