Struggled six ways from Sunday to find a good position to hold the canopy to solo-rivet, without mangling 20% of the rivets. Finally found a workable but not perfect way to secure the canopy frame to the work table using the hinge arms and raised blocks screwed to table.
The clamps are ok, but the perfect jig would have a temporary pin thru the hinge bushing AND a downward clamp to hold the c-channel. Needs to be secure enough to buck and drive solo.
Sequence of assembly imperative; skin fwd edge to c-channel, then sking to stiffener row, and finally the stiffener to the channel (blind rivets).