RE: Idea what this plane is/was
I would say it is not a Falcon 56 for a few reasons.
The whole tail assembly looks wrong. The fin appears to be constant chord, while the Falcon's was tapered to a shorted chord at the top. The Falson didn't have tip fins, but those could have been added to compensate for the forward area of the floats. The Falcon had a definite airfoiled stab.
The Falcon 56, as I recall had a semi-symmetrical airfoil. You could vary easily trim the leading edge of the ribs before gluing on the pre-shaped leading edge and make the airfoil fully symmetrical. I did this on a couple. Also, the original Falcon had a heavy spar that ran through the ribs. It did not have top and bottom spars as this plane does. I can't speak for the Mark II version.