Hi there,
and thanks for the maintenance manual. I was able to locate the chapter about the keyboard and got to work. What I'm able to gather from all of this that the gap actually exposes the battery (even worse?) and keyboard is one millimeter too short 
Please let me explain and show you a couple of photos (they show the problem really well now).
1. I unscrewed the keyboard. It has to be pushed forward in order to release it. The volume button panel is an inseparable part of the keyboard, meaning, it cannot be 'tweaked' individually.
2. By pushing the keyboard towards the screen it is immediately apparent that the keyboard sits really well in this position, sort of 'clicks' into position, as if it was meant to be this way. Unfortunately it is not possible to leave the keyboard like that, because it is now detached from the trackpad side (leaving a gap there).
The only possible position for the keyboard is the one that leaves the gap visible, exposing the battery to whatever spills you might get on the keyboard (granted, the computer is spill-resistant, not WATERPROOF, but for the price I expect build quality).
I have one question remaining:
1. Is leaving the gap there a conscious design decision from Lenovo and all Thinkpads are like this? I'd be interested to hear other people's findings.
Kind regards,
Kimmo
PHOTOS:
