I know you asked for a '69 but I suspect '67 was the same. My 67 assembly manual shows the stick as a separate item so I assume it was added when the engine accessories were installed during the car assembly. What does the '69 manual show? On my original unrestored '67 L35 the dip stick body still retains the factory black finished, though it is faded and I can't tell what the gloss level was, but it is definitely black. I have the notes to my other 67 I restored in the mid-80's and I recorded it black as well. Hopefully someone here with a 69 BB will chime in.