My conversion is complete.

I used a small piece of 1/8" ply to spread the load and give the screws something more substantial to bite into. The wire supplied with the Dubro tail wheel turned out to be too short so i bent a new piece of wire and added some trailing castor as well.

Also note that the wire that is inserted into the rudder is bracketed and clamped by the control horn which will help to ensure that the wire doesn't tear through the balsa rudder.