Nagging feeling that the aperture after new scuttle in a little tight.
Not much to worry about there n terms of alignement, in my opinion.
I had wondered that too in my own case myself before it came to re-fitting the screen. I had taken no before/after measurements.
However, upon careful reflection and inspection, I decided its almost impossible to tighten up the aperture unless you are re-modelling the corners with some metal, ands the edge of the scuutle to be attached wit welds is aligned with the bottom lip of the screen aperture.