My fav cutting tool is the 1mm blades for the 4 inch grinder, the thin ones. If you can cut it proud (not quite to the original shape) and then finish with a file to get the right shape. A couple of points.
It may seem like a big deal to cut but there is nothing that can't be repaired with fibreglass or steel.
The template for the left can be flipped upside down to be the template for the other side.
If you want my number i can PM you it and i'll walk you through it.