Yes, there is a metal tab that normally sticks up and rests against the neutral safety switch. It is this tab that moves the switch when you shift between the gears. It breaks VERY EASILY. I did the exact same thing when I was messing with my steering column as well.
You are going to need to get another one from a pick a part or somewhere if you want your neutral safety switch to work (it also handles your reverse lights). Or you can wire around it and disable the switch in the meantime or unscrew it and let it hang and manually hold it in place to start your vehicle (which is what I did till I found a replacement). Once you have the truck started, you dont need to hold it in place any more. I found a quick video of a guy trying to figure out what is wrong with his (on a 73 which is still setup the same), but he uses the same starting method and the video shows the tab you are missing at 3:30 of the video. You can see it here:
http://www.youtube.com/watch?v=AdIqRl-5cNo
The tab is attached to a half circle tension piece that fits around the shifter. On the top of the steering column right in front of the switch you have pictured, you will see (use a mirror) a hole in the shaft. That is where the piece sits with the tab sticking out. Here is the part you need in the Dennis Carpenter catalog:
http://www.parts123.com/parts123/yb.dll ... Z50000024D
You will need to pop the old one off with a flathead screwdriver, and then pop the new one on. It can be a pain, but I have done it 3 times now. Dont ask why...
