@robadob, I imagine even if you could "straighten" it, it would be impossible to get it close, or exact, enough to be a good fit anyway and therefore not worth the effort. I has the same issue, my one was out by 20mm, and "fixed" it by fitting a new door jamb all the way around. I routed it to be decorative on the front and installed it on top of the "built into the frame" jamb. I had enough space that it didn't interfere with the yale/mortice.
I split the difference by moving the top hinge a bit too, so that I had gap of 10mm in two opposite corners.
Whilst I was at it I also fitted hidden QLON (AquaMac 63) draught sealing into the new jamb. It's been on 17 years with no issues.
I should say I made the new jamb as I had router table at the time so it was made exactly to fit but I reckon a joiner could knock it up fairly quickly, it's only a bit 20*10mm timber routed on two edges.
@robadob, I imagine even if you could "straighten" it, it would be impossible to get it close, or exact, enough to be a good fit anyway and therefore not worth the effort. I has the same issue, my one was out by 20mm, and "fixed" it by fitting a new door jamb all the way around. I routed it to be decorative on the front and installed it on top of the "built into the frame" jamb. I had enough space that it didn't interfere with the yale/mortice.
I split the difference by moving the top hinge a bit too, so that I had gap of 10mm in two opposite corners.
Whilst I was at it I also fitted hidden QLON (AquaMac 63) draught sealing into the new jamb. It's been on 17 years with no issues.
I should say I made the new jamb as I had router table at the time so it was made exactly to fit but I reckon a joiner could knock it up fairly quickly, it's only a bit 20*10mm timber routed on two edges.