There's a lot of similarities to the Rubik R-14 Pinty, but a lot of significant differences, so it doesn't appear to be that!
So maybe it's the (unbuilt as far as I know) two seat "improved Pinty", the R-19 Pinty II ??
Have to be OH if correct as I'm going to be very busy for the rest of the day
Edit: Ooops! I just noticed that Brian said that flew off the drawing board, so that would seem to rule that out unless I misunderstand his meaning!! Oh, well, no time to dig deeper, gotta fly (I wish
)!