I tried that exact tail fin but I found it too flexible. It would bend out of the way and my tail rotor would strike the ground or the tail fin itself. I guess it didn't work as well for me as it does for Doug.
If you put a bead on the end of the rod, it won't dig into the ground or flooring, and may never break. With the current version of superskids, we use the fin to support the tail rod strut as shown in the attached picture. It really helps to strengthen it. In the next superskids revision (due out in about 6 weeks), the tail fin will be clipped to the rod and the bead will be included.
If you think you can drill out the old rod and put in a new one, I think I have an extra fin and bead I can send you, free.