But wait...there's more. There has to be a way to attach the fence (or haute piece) to the armour, so I created tabs. These tabs will bend 90 degrees, and will be used for riveting the haute piece onto the pauldron.
Also note that this method will create a haute piece which will be at 90 degrees to the armour. If you didn't want it to be exactly 90 degrees, then you would make the opening an extra couple of centimeters wider. Forget formulas...this will be a matter of winging it if you do that. Maybe another time.
The last thing you have to do is to design in a roll allowance of 2 centimeters (half inch) and to provide straight sections near the ends. And below, I have laid the above template onto the steel, cut and sanded it, and designated which will be the inside. They look symettrical front to back. Right.....sure they are.
And here is the collection of tools required to do this little job...the power shears and dcompass. I have decided to not use tabs, but rather, to just bend the inside curve up 90 degrees, and get on with rolling the outside edge. Nothing new there...just a lot of careful work. Laying out, cutting out, shaping, and rolling took about four hours per side, including drilling and rivetting the haute pieces onto the spaulders. Not too bad. Not a beginner's project either!