Sorry to get into this discussion late, but I am a new member to this site. I also have a choke/throttle set-up on my car which was installed a few years back. The throttle was never hooked up until just recently after I saw the photo on eBAy. You are correct in that it doesn't work the way shown. When I purchased this set up, it came with the more square knobs. Since then, I've had to replace the throttle knob and obtained the more rounded one. So now my knobs are mismatched. Also I found the screw insertion is on the opposite side. The rounded one is on the left side (inside) where the square one is on the right side (outside). Is this consistant with everyone elses? Thank you, John Holland 1970 Green