This is a chronicle of my last big project at Wally’s. I started with a Martin sousaphone with missing pistons, top and bottom caps, neck and tuning bits. As one can imagine, the availability of these parts is negligible at best. The only recourse was to find a replacement valve cluster and install. A project like this comes with unique challenges involving the positioning of the cluster to facilitate proper hand and mouthpiece positions. Intonation is always a concern, but as it turned out, the Olds cluster mated well to the Martin with few adjustments.