Reveal boarding when window is out of square?

[Shell1948]

Hi all.
We are replacing rotten battern/dry lining around old crittal windows. Our new wall corners are straight but the window is lozenged.
What is the best way to fit the window reveal to make the best of the old window fit?
Many thanks in advance
Shelly

 

[Monkey Boy]

Scribe it to the window

 

[ChrispyUK]

Hi all.
We are replacing rotten battern/dry lining around old crittal windows. Our new wall corners are straight but the window is lozenged.
What is the best way to fit the window reveal to make the best of the old window fit?
Many thanks in advance
Shelly

Keep them plumb (ish).

Will out of plumb windows be more/less noticeable than the reveals once everything is painted and decorated?