SUCCESS! See some pictures below:
I have not attached this to my control panel yet, but I believe I am past all the harder stuff (well .. it really was not all that hard).
I kept the metal tube which came with the Gorf handle for mounting, but cut the length a bit for the correct size. I then took some black sprinkler pipe (ie: funny pipe) and drilled some holes so the mounting screws (from the Gorf joystick) would go through the black sprinkler pipe as well. I then placed the sprinkler pipe up inside the metal tube. Next, I placed the wiring I needed through the sprinkler pipe so it comes out both ends.
Now, after removing the top oval-like handle from my Super joystick, I was left with the long silver rod. I shoved the long silver joystick rod up into the black sprinkler pipe (next to the wiring). Due to the wiring and the silver rod being together in the black sprinkler pipe, it is a real tight fit, so there was no need to use any mounting screws to secure the silver rod at all.
NOTES:
I did originally try to secure the silver rod with one of the Gorf handle side mounting screws, but the screw did not really provide enough force to hold the silver rod in place. However, after placing the silver rod inside there with the wiring, it was clear that it was a real snug fit and mounting screws were not needed anyway to make it secure.
In order to remove the top oval-like handle from my Super joystick, I simply used a hand-held scroll saw. I put the pulsating (up/down) blade against the silver rod and cut one side of the black oval-like handle off. I then placed the remaining black handle part in a vice and pryed the silver rod (quite easily).