Hount, you could try to build one with an N900 keyboard for yourself, Dirkvl did his first prototypes with an N900 keyboard, so we know that it works. You will likely have to buy a used N900 and butcher it for parts to get the keyboard and domesheet. That is not an option for Dirkvl when he is building 75 of them, but OK when just building one.
Is your OH completely flat when closed? On mine, the top side of the external layer (where the camera hole is) is 2 mm away from the main part, while the bottom side firmly touches the main part. I tried to correct it but couldn't. The result is that the half profile is not "straight" when closed.