Wonky door frame - what to do?

[chaoticbob]

I'm doing battle with with an old house. There are many challenges but I'd hoped to defer the kitchen door until I'd gained more confidence. For reasons to do with a dog it's become more urgent, and my wife proudly came home with a a ledge and brace door which might do the job - it's about the right height and only 2 inches or so short on width. Easy-peasy I thought, but not so:

Everything is out of square and the jambs aren't plumb or parallel. The door itself is (comparatively) square.
Any advice would be welcome!
Rob.

 

[DBT85]

Is that a 10mm out over a 300mm run? Your house is drunk!

Given the other works going on surely putting in a new liner would make sense? You can make sure its square and plumb and then the door is easier to fit too.

How out of plumb is the side? The photo has your squares bubble off to the right, but its registering off the top of the frame, not off the side. If the side is plumb enough you just have to cut the top of the door out of square to fit the hole.

 

[LBCarpentry]

Cut a scrap sheet template of OSB or similar to fit the frame and make a judgement.

Worse case remove the lining and refit. I like to try and retain as much as possible
Louis