Help identifying unknown part

[Knight72]

Hey there guys, I am new to the forum and have been lurking for a week or two, and could use a little bit of knowledge from people familiar with these trucks. I recently purchased a 72 c10 lwb and I am in the process of getting her up and running. I am trying to find out what the black knob to the left of the white brake release t-bar is in the picture below. I thought it might possibly be a manual choke knob, but haven't seen one under the dash on any other trucks in threads on the forum. Thanks in advance.