> Is this just half of a Serrurier
The "real" Serrurier truss was developed for LARGE (4m+ class) telescopes where tube sag is a real problem. With sizes and weights amateurs are dealing with, it isn't really a Serrurier truss at all (whose main advantage is not to prevent the sag, but to allow the controllable amout of flex on both sides so that deflectons cancell), but just a "non-brand" truss structure, known to mechanical and civil engineers for centuries. The "real" Serrurier can be recognized by its so funny looking extra thin lower truss members (compare elements on upper and lower parts on Russian 6m scope for example).
Bratislav