Windscreen gap minus rubber

Can anyone help me out with what the gap should be around windsceen minus the rubber seal? And also the tolerances? 
Mid way through scuttle panel change and want to make sure its going to fit with no leaks!
It all looks fairly even and the panel lines up pretty well but have a 9-10mm gap on both sides and a 11-12mm gap top and bottom. Theres around 1-2mm difference as you run along the panel.

Any help much appreshiated

Thanks