First, thanks for all the support !
Secondly here is a small update on the progress. It’s actually amazing what ideas come to my mind 3am while carring my feverish 6 month old child around.
I hope this shot is ok, since it was taken from my android phone from the Onshape app.
What you see is the bare form of the carry middle part.
The rails were moved from the rim of the shape to the side. This solves I couple of problems for me ( the gray part ).
on the lower left are some extrudes that should help in keeping the lids in place once the are closed and secured with the bars.
I also have done some prototype printing on the rails to see if the fit and to no suprise , they don’t (but I’m very close).
Next will be the bars on the carry to mount the keyboard, so please be patient