The tail wheel wire being imbedded in the rudder is not one of the brightest ideas Sig came up with. The relatively soeft (light and good for the rudder...) is not good for retaining the wire. It will eventually wiggle loose or break out.

Putting in a Du-Bro tailwheel bracket is a good idea, but the lite play isn't great for retaining the screws... so you'll need to double the bottom of the fuselage wherre the bracket mounts.

Fortunately the 4* tends to be a bit noseheavy, so it should be no big deal having to add the weight to the tail with the heavier tailwheel mounting system.

**************

As far as retaining the tailwheel. You can use a wheel collar, or if you have the correct tools, just put a 90 deg bend in the end of the wire. I used to also solder a washer onto the wire to retain a small wheel, but we only had metal or wooden hubs on the wheels back then. (don't solder a washer on if you have a plastic hub....)

If you want to be REALLY fancy and you are REALLY good... heat the end of the wire cherry red and let cool, then drill the wire and use a washer and a piece of copper wire to retain the wheel. (that takes one heck of a tiny drill and you have to be VERY good to do it.) Smallest I have done that for is a 1/32 hole in 3/32 music wire. I have seen it done to retain a wheel on 1/16 wire with a 1/64 hole. (scale model... he made his own cotter pin for true scale wheel retention.)