Gazim,
it looks like you have a Hurst Shifter. If you look with in the Hurst website you could find a shifter lever that will bolt on the shifter. Ebay has been pretty good for me to find a few things I either am looking for or to see the different variants of items.
I purchased a Hurst shifter off of Ebay.
Shifter . With the help of an good friend, we made the old shifter lever attach to the shifter.
Mock up mock up 2 hole drilled finnished shifter and lever shifter box, shifter lever w/knob What ever you decide to go with, there are several shifter to choose from, you will just need to put in the time to look to see what will work for you.
By the way, NICE truck. It made me miss my old 65 fleet side.
Bread