The wishbone topstay binder was previously brass brazed using a preform ring placed inside the 19mm topstay tube. This photo shows the silver brazing of the topstay binder to the rear of the seat lug. The binder itself is milled from a piece of 4130 round stock and mitred with a 31mm mitre cutter to match the diameter of the seat lug at the angle of the seat tube/topstay joint.