I've come to this topic a bit late as I wanted to get my Survivors list up-to-date first. If you go to
http://www.catalina.org.uk/survivors-list you can download what is arguably as good as any Catalina Survivors list and it is up-dated roughly every six months. Some of the aircraft are listed as 'airworthy' although this description can be subjective - is it based on, for example, aircraft that are capable of flight but have not flown for some years (such as N315KM in Greece) or on examples that have flown in the last few weeks such as G-PBYA in the UK? Make your own mind up but at least it can be used as a pretty good guide.
Elsewhere on the site is
World Catalina News and the latest edition is not quite so up to date as it does not yet cover the demise of N85U or the recent return to the air of C-FUAW. Again, it is updated six-monthly to coincide with the publication of the printed magazine
The Catalina News.