Mark/drill 1/4" holes 1 1/2 " apart on each 2 1/2" segment, drill 1/4" holes at side center of each. De-burr each hole. Saw segments apart. Best to drill all the holes with it as one long piece.
Each section is cut, then filed smooth, bolts test fitted.
Drill 1/4" holes 1/2" in from the end of each 1/2" conduit piece.
The plumbers tape will be cut into 6" pieces, with the sharp corners folded over. With the bolts, the tape will clamp the 1" dia. 8" long 1" conduits pieces to the trike uprights.
The tape clamps the 1" conduit to the frame tube leading towards the handle bars. 2 pieces of tape per tube, one at top, one at bottom.
The "U" segment in place beneath the shade board, with the side bolt through the upright 1/2" conduit piece.
The rear 8" conduit segments are clamped just at the top o each rear upright with plumbers tape and 1" bolts. The 1/2" 3 foot tubes are inserted into where they will slide up and down.
The front upright is off-set to the left slightly, to allow the steering to clear the post on tight corners. Again, clamped with plumbers tape and a bolt, at top and bottom.
Steering turned left easily clears the upright tube.
Roof/table high enough to sit down and drive / pedal out and about.
This old board isn't the final roof surface, and it will need to be levelled to be nice and even when done. Ping pong or foosball? 'Up' and a 'Down' positions, shady, it now has many possibilities...