Interesting Engineering project.
My first idea would be: Flip out display!
Have a look in the car audio market, as car radio makers have also had to find a solution to overcome the limited dashboard space. Your requirements will not be met with a standard flip out system of course, but you can immediately see the benefit of having a flip out display that can go over the barometric instruments once there is power available from an engine driven generator.
You will have to solve some problems like doing the alignment preflight and so on, but concerning your space problem you definitely have to add the flip out display to your morphological diagram.
Cheers!