I'm also sorry to see that you've had no positive replies yet. The design looks orthodox and I'd like to see one. I have to say that I've been flying seaplanes off and on for about 15 years, been to the Sun-N-Fun splash-in many times, but never seen one of these - it it was a 'winner' you'd think there'd be more around (and in the air, not hangar queens)...?
I did a little research and before you read on, a disclaimer - you can probably find a long list of accidents in any type aircraft - homebuilts are hard to be conclusive about since you can name the thing anything you want. Indeed, some of what I found might not even be Catalinas:
I found 9 accidents in the NTSB files for "Avid Amphibian", including 2 fatal, going back to
1992. Here are the links (I left out one that was an unexplained engine failure, though now I see that there's another that said no carb heat system installed...):