Righty, if you look closely at the photo, you'll notice the that wire does not run at a 90 degree angle. My rudder is also on a slant but that creates no problem whatsoever. The wire is like an extension of the trailing edge of the rudder. Note the wire does not attached to the bottom of the rudder as many tail wheel assemblies suggest but rather is attached to the trailing edge. I'm sure this (or some slight varient) would work. It took me about 10 minutes to do (counting the figuring it all out).

A sorry to say, Willdo, but steering with just rudder is simply not possible until you reach a certain speed. Or have an incredibly powerful engine that sends a ton of prop wash over the rudder. Of course if you set your plane pointing straight down the runway you will after a bit of a (basically uncontrolled) running start be able steer with the rudder. But if you want to be able to set the plane down and then taxi into position you HAVE to have a steerable wheel.