Andy, if you go back to post 135 you will see I cut two pieces of 20mm form ply the desired shape. These were tightly clamped each side of the panel. It is then simply a matter of tapping gently all the way around the circumference just slowly stretching the panel bit by bit. I used a nylon hammer to minimise bruising the sheetmetal. If you hit too hard in any one spot you can over stretch and tear the panel. It is all about taking time to work it slowly. Each guard took about and hour. You can do an awful lot of panel work with pieces of angle iron,flat steel, and a lot of clamps. I find a swivel vice mounted on a pedestal that you can work all around much more versatile than any bench. These methods I find are more accurate and versiitile than folders. Lots of small folds can be done with pliers. Everything then needs finishing off with a panel hammer and dolly. Cold rolled panel steel is very malleable and designed to work like this.