Hey guys, at least I found a kind of flip case fitting for my needs.
I don't carry my Pro1 with me a lot, so the bulky design doesn't matter and it's well protected at home 😄 I've bought it at this Etsy Store, not sure about international shipping but she's located in Munich.
I like the idea of wrapping this elastic plastic stripes round the edge of the keyboard, so the display can close properly.
If you order you can tell an individual phones size, choose from the Pro1's data sheet h: 154mm; w: 73,6mm; d: 8mm (depth only keyboard). I also asked her to make the whole bag 5mm wider