FFWN is 'Symphony of Voices', aka flag (it's a 320). FZUH is the TCA 319 and GQJA is the *A CRJ2. Haven't seen a *A CRJ7.

But to topic, just how thorough of an 'experiment' could the naked 762 have been ? Surely it hasn't had time to oxydize or whatever else the downside of not painting it is. And I would have thought it needs more than a month or so before the fuel savings (if any) could be accurately assessed. Maybe the brass simply agrees with most of us - it just looks like ****