A simple substitution experiment

[ReneZ]

So do you have a specific approach to decide what my 'cipher text' above would be?

Yep, bang it into Guballa Substitution Solver,  try different languages , see that Spanish produces Italian looking plaintext and put that plaintext into a Search engine 
and bingo "Nel mezzo del cammin di nostra vita" --> You are not allowed to view links. Register or Login to view.
Guballa --> You are not allowed to view links. Register or Login to view.

I am curious to see this Italian looking plaintext. Do you still have it?
So you found the true solution, but that was based on the fact that the plain text is known from other plain texts, which may not be the case.