The angled metal connectors being " off " will affect the tightness of the frame/windshield in the corners, but not the height of the assembly at the top. Mine leaks around the lower right corner, as well as a tiny drip from the top center right.
I used a Steeles Rubber gasket which is very flexible. Have found that when I close the windshield, if I " tweak " the gasket edges a bit, it seals pretty well.
As for Factory adjustments, I recall seeing a video of a family in Russia taking delivery of their brand new Lada ( after waiting 2 years ). It rolls off assembly line, but won't start. Guy pops the hood, hits motor with a big hammer, and away they go !. I suspect GM quality control was similar in '40s'
