In 1981 Paul Rivera created a 5 year master plan for Fender guitar amplifiers that detailed descriptions, features, functions, price points, market positions and more. The All-Tube Stage Lead was part of that plan. This single prototype was hand-built. However, the decision was to use that name on a future solid state amplifier and the tube version was never released. This one is the only one in the world. Some of the features included Paul Rivera's pioneered effects loop with level controls, mid-boost, foot-switchable gain-boost and more..
https://www.rivera.com/