Jumping back up the thread a bit, i found this Alan while generally trawling YouTube.
While not immediately apparent as to why i think it's relevant, it does deal with the multiple-compound curves that may be found on a windscreen surround - not necessarily in an orthodox way but in a way that works.
Quite an interesting video in general and while i know you can weld, it might yield an extra clue or hint you can adapt/improvise when you do GAMs windscreen surround.
https://youtu.be/EhGXSM3MZEQ
It's quite long but has a lot of useful info in it that can also be transferred to other repairs, he's got quite a strange accent as well, a curious mix of Irish and American so some bits need rewinding and viewing again to understand what he says. Enjoy!
