Here's a pic that shows the tabs on the original wind deflectors:
I do not recommend allowing an elephant to sit on the original deflectors.
When I first made mine, I was going to have a folded edge to fit inside the rollbar. It was unnecessarily complicated.
My recommendation is to just use a flat sheet cut from the perforated aluminum. Make a cardboard template that rests against the rollbar slightly within the curvature of the back. I didn't have to remove the padding to apply the zip-tie, but just slid it underneath. A thin strip of 3M tape applied to the rubber edge will secure them and be less visible than the zip-tie - I may do that later.