Once you have the hood made up, the easiest way to make the framework (which consists of three hoops of steel strip approx 7-0" x 1"x 3/8") is to fit the hood first with some temporary support and then to bend the strip steel into the shape of the hood afterwards. Below, the pictures show the brackets for supporting the frame at each side of the bodywork and the way that the spacing of the supports is achieved with ordinary washers. The hood is then attached to the frame with strips of Velcro.' These words and pictures below courtesy of John Bircumshaw.
Frame spacing above ^
and off side bracket below v
Pleat, gusset or tuck. I don't know, ask your wife.
These two images of roof-frame instructions are from Chris Cogan
Measurements are intended to help with the Triumph based Midge.
Body style variations will require adjustment.
Make a template up out of your best bed sheets, and use it as a liner later.
(Perhaps you should check that with your wife as well)