[Milt K from Pa]

Fredy,
The photo you supplied has a missing part. There should be a "C" channel riveted around the body . This channel when new had a cardboard inset in the center of the channel, for nailing the convert. top fabric. You can see all of the old holes in your body for mounting the channel. I have heard of replacement steel channel being made in straight lengths, which would require a lot of work forming around the body. A tack-strip material, of vinyl, can be had to install in the center of the "C", or some folks use "Quick Poly" resin as the tack strip.

Milt K from Pa