It worked, Yeah!!
I got the rest of the steel that is in the way removed.
Got a new piece of cardboard and glued molding to help keep it straight.
Marked a straight line on the roof to line everything up to.
The molding keeps the cardboard nice and straight.
I used a compass to mark and cut the curve in the cardboard.
But it still does not match the roof. I angled one side and it lined up perfect, at least for a bus perfect.
I decided to score the center and cut the molding and bend the cardboard at the center.
I was able to use the old side piece as a template for the new. the new side piece is just 3/4 inch longer.
Drivers side done.
The window fit with no gaps