The following is an excerpt from a letter written by Secret Service Chief James Rowley to (I assume) the Warren Commission.
In a photograph attached and labeled exhibit 2, taken by the FBI, there is a dent in the chrome topping of the windshield, just above the attachment of the rear view mirror to the top of the window frame. SA Geis, who was responsible for the care and maintenance of this vehicle, believes that this damage was on this car prior to November 22nd, 1963, and it is his recollection that the damage was done in New York at the Empire Garage (Lincoln-Mercury Dealer) on November 1st, 1961. Geis thinks the damage was done while he and employees of the Empire Garage were removing the “header” on the leatherette top to make repairs to the crank which secures the convertible top in place on this vehicle. If this was the case, no effort was made to repair the dent prior to the assassination.
Mr. Paul Michael, Service Director of the Empire Garage, who was present and assisted during those repairs, in an interview said that he did not remember that any damage occurred during those repairs but that it is very possible that it could have happened as a crank had been broken off in the area. The repairs were done hastily since the car was needed to transport the President, and this slight damage might have gone unnoticed by him. It may be significant to mention here that this photograph accentuates the damage. This indentation is so slight that it could pass unnoticed in ordinary viewing of the area, especially since the sunvisors, being in the horizontal position most of the time, would frequently cut out the view of this portion of the frame.