First step was to prototype the shape. this is just gluing a bit of a skeleton together, just to get the features in more or less the right place

as it is here, it’s just a bit to straight up and down, what I really want is for it to spread out a bit. So I glued on some panels that were attached at the hat band, but stood off at the points by a strut, just holding things in place. I then covered the new parts with a sheet of paper, taped into place.

the next step was to simply cut the new outer panel off the structure, flatten it out, and place it on a clean piece of cardboard to trace around. After cutting the new bit out, bending it back int a hat band and glueing it together, reinforcing the edges.

The final step before painting was to add a raised edge

then of course, everything gets covered with a layer of tape to hide the seams, and a paint job.