Have we ruled out simple substitution unwisely?

[oshfdk]

I was suggesting this to see its affect on entropy, not as a decoding attempt. 

I can't say much about the entropy, I know how it works on paper, but when I tried computing it almost each and every single time I would overlook something and get some bogus results. So, I probably cannot add anything to the entropy discussion. 

Simple substitution won't work for many reasons and for me the entropy is not the most important of them.