[Request for advice] replace a 2-fold plate thermostat

[frede]

Hello,

I face some issues with my old EIB wall thermostat that is not displaying some useful info anymore (current and setpoint temperature).
Here is how it looks from the outside:
IMG_6705.jpg
And from the inside:
IMG_6308.jpg
There is only one bus wire.

What would you do if you were at my place?

My preference would be to install a Zennio Z40 screen but there's the problem of the hole left by one side of the 2 fold plate...

Thanks