There are still quite some FP1 users out there, so I’ll update this thread:
Even though my old case was still fine (even though the black has faded to something more blue-ish), I finally bought a new case by shapeways – roundwithgap – that has a little extra feature: the custom-made case now has an additional gap/notch so you can use the Quick Access App more easily.
I’m totally happy with it.