1988 4+3 overdrive knob

I've been looking for a new overdrive button for my 4+3 shifter knob. If anyone knows of where I can get one, please give me all the information you have as to phone # part# ect. Thanks!

Good Luck finding one of these, I have been looking for years. I finally rebuilt the plastic prongs on the bottom of mine and it works now. GM doesn't stock it any longer, neither does Mid America. A salvage yard might be a source. Later, KN