thanks to all
the housings I'am looking for cannot actually be from Pelikan, as their locks are all mounted on the side (as far as I could see).
the lid goes over the rest of the housing. This does not work
here, as the housing must have a frame for attachment to the arch.
The attached pic show an example from a very simple, very small (and probably of a much lower quality) case with this frame but without a lock.
I checked also some cases for trucks. But when they will installed vertical instead of horizontal (which is standard) they are not waterproof (because of the locks).