jUST HAD TO DO A REPAIR TO MY 35 CHEVROLET CLOCK MIRROR TODAY.
The clock came lose from the mirror part and hit the heavy carpet floor. The one time arm, top one , was lying on the carpet, I looked at it with glasses on and saw the clock arms post was splined, so just gently used my finger tips and put it back on.
Still on after driving around for 3 hours.
Looking at the one listed for sale on ebay by tigerjones33, appears that the center pin is pressed over and rounded. Different than the one for my clock mirror
mike
