I fabbed these aileron stops, according to a plan from Mickey Coggins (Thanks!) I used a standard Nylon bushing ID 8mm and OD 12.5mm. The most difficult thing was to get these critters in! In the end the only thing was to loosen the flaps again and to manipulate the bolt/bushing combi in its place. I had to Superglue a washer to a nut and this again to a wrench to get the final nut in its place!