Frame with 3 Roof Supports

Here's the frame with side metal rod supports, wood dowel support in the back axle, most joints glued, and all three roof supports. I found a place to order schedule 20 PVC and some 90 degree Tees for connecting to the support in the corners and the two sides at 90 degree angles. I'll get a photo when it's here.
The schedule 20 PVC is called Class 200 on the website from which I ordered. It sounds like the same thing. I hope it is.
I had to redesign the top to be longer, plus an extra pipe going across above the roof for surfboard racks. Again, photos will do a lot more than words.