Hi Sean...

Just got off the phone with a friend of mine from the bugsmasher flying club and he said that the ERCO (Engineering and Research Corporation) Ercoupe did have rudders but they worked in conjunction with the ailerons.
He also corrected me about the engine, the original Ercoupe was a 65hp and not a 75hp.
Cheers...Happy Landings...Doug
Aha! So you
don't have X-ray vision... ;D
Actually, I though maybe you could see where some external linkage was missing or something.

The conversion (which has been done many times to Ercoupes of all vintages) is simple enough... I think the cables and pulleys from the ailerons to the rudder horns are removed, and they are simply connected in the usual way to aftermarket rudder pedals. Supposedly makes it more fun (you can slip!) but with the basic design and the very effective trailing-link mains, it is simply not necessary, even in a stiff crosswind.
But either way, to coordinate turns, the rudders have to move somehow.
You should know by now that all airplanes with the horizontal stab at the "wrong" end need moving rudders, however they might be moved.
Into the corner with you, with your copy of Langeweische's book (where all that is explained).

And take a look at most of Burt Rutan's canard-equipped designs... there's a vertical stab, but no rudder.