Heavy Duty 1963 Pushbutton 904

I purchased a 904 slant 6 904 a couple weeks ago. I noticed that the speedometer housing is plugged with a brass cap, I am guessing this was done to keep tranny fluid from spewing all over the place. This tranny was supposedly used for racing. Now, that I am looking it over, I only see one cable attached. So since I am a transmission dummy, I cannot find where the second cable is supposed to attach. This would be the Park Lock Cable, I think. Does anyone have a picture showing how this cable enters the transmission?