Dave, it took me two attempts to get it how I wanted it. I had to live with the first attempt a while and ponder it from all angles before I really knew what I did want.
I got lucky with the curve, it took all the strength I could muster to form. Clamped the scaffold pole & ali to the bench with two 8" g-clamps and some 4 by 2 blocks. Kept the ali over hanging the bench as much as pos. Then pushed up on the ali from underneath with another length of 4 by 2, keeping the force as uniform as pos along the sheet to form around the pole. The front slot was cut afterwards.
PS - Hope there are no professional sheet metal people reading this!!!!
