Thanks to work I could bring a brief visit to DUS. The following could be photographed:
Take note that entry to the terrace at the railwaystation is somewhat awkward nowadays, as the central hall is completely empty. The small shop is gone and the escalators are out of service. You can still buy a ticket at the airport info desk, but you'll need to use the elevator to E2 to go up. When on E2, go to the right and then there is a door where you need to ring the bell. Via the camera the man at the info desk downstairs will look if it's you and then will buzz you in. Quite a hassle.
Also take notice of the fact that at nearby Mönchengladbach a Fokker 50 in All Nippon colors is present. It is registered OY-PCL. It should have been outside, but when I arrived, it was just being towed in... To bad!
Well, hope you like the pictures!
Cheers!