Dear @bambuka, as you yourself stated in the rules, I solved my puzzle in the comments under my post after the contest had ended - you were mentioned ;-))

https://steemit.com/hive-185836/@weisser-rabe/rpo0h7

But I will gladly change the original post as well...

Meanwhile, my choice is... No. 1.
@rut-ru has transformed a not-so-nice, sterile-cold building and created something sleek.