[kevlar]

"It looks like with your pvc pipes, you were able to make angles work by using PVC T-connections as a swivel." -

A little swivel and (don't tell the wife) heating of the PVC in the oven to about 110 degrees, then I was able to "form" it to the shape of the cab.

"I see lots of screws in the photos. Did you just use self-tapping screws
straight through the FRP into the PVC tube?" -

I used the self-tapping screws to hold the shape ( careful not to over torque)after I heated it, and pushed it slowly into shape until I could fasten it down, leaving the screws. I then backed up the screws with 1/2 inch saddle straps, nuts and bolts from the inside.

"Did you have any trouble while heating the panels to bend them? Any over melting, or heating the tube underneith? "-

At first, I was heating too quickly and switched to a further, lower heat with a wide flame adapter. If you heat with long, sweeping motions, watch, bend on the line you want, you should be alright. kind of like making the panel rubbery at the line of bend.