It depends entirely on the aircraft. The British did not use many turnbuckles, most of their aircraft were rigged using streamlined flat wire which did not require turnbuckles, they did however use turnbuckles on the control rigging, some aircraft had these turnbuckles hidden inside the fuselage. Most other countries used turnbuckles, there was only one per rigging wire usually near the bottom wing for ease of access. Numbers depended on the size of the aeroplane, if it had one, two or three bays, on an aircraft like the Albatros there were less then 20 turnbuckles, but on the Voisin III there were over 150. It won't matter how many turnbuckles you make, the ones you don't use for one build will come in handy for the next build.
Des.
