RE: Idea what this plane is/was
It's a good possibility that it wasn't a kit, but an original design. We used to do this a lot back in the 80's for funflys and float flys. From the looks of it, it was built with economy and quick building in mind. Just what you would want for fun flys. If you broke it, it didn't matter too much because it was easy to build and cheap.
The plane in my avator is an example. Built off the ugly stick design, but improved for better manueverability.
Frank