70-71 AMD Fender fitment woes

Looks like you have quite a gap at the cowl. I would start with readjusting that first. Maybe the fender could be set on floor and pushed down on to gain back the bow that is missing. I think you're right about it being flattened out or squished. Does it sit high next to the cowl? That would tell me that it has definitely been flattened.
We have taken the door all the way in at the top, at the cowl to try to gain as much as we can but the gap is still too much at the fender/door joint.

The fender does sit flush with the cowl (height wise)

I’ve tried bending or adding more bow already but that support on the back of the fender makes it too rigid. Maybe I need to try again