I think they forward arch connection is the piece of canvas that goes into the plastic piece on the arch. I replaced a section of the plastic last year. It comes in very long sections and they are straight. Formula offered to ship it via freight delivery but it was over 20' long so I couldn't move it if I got it.
I had them cut the one piece into 10' sections so it could be delivered via ups.
I had a break in the corner that needed replacement. I was going to go up the side and around the corner with a new piece but decided on just cutting the bad section out and I'm glad I did. The pieces are straight and have holes in them for screws but the screw holes didn't line up with what I had. You have to bend it with a heat gun and I had to drill and tap the arch also for the ends. The drill and tap is not easy to find because it is so small, I ordered some at Grainger, be prepared to break a couple.
It was a real pain to do but I did manage to get the section replaced. With 6 hands, 4 clamps, 2 heat guns, some double sided tape, a couple drill's and taps and a ton of patience it's a manageable job.
