My first Bird was an early production Van Nuys car (LOS on the data plate). Had the deluxe seatbelts, custom interior, straight headreasts, straight bar vent balls and came with a single horn. PHS docs dont show dual horn option and it wasn't included because of the interior.
My current Bird is also a VN car (later production). Deluxe seatbelts, custom interior, + vent balls, angled headrests and a single horn. PHS docs for this car also fail to have the horn option.
I am pretty sure they were an option unto themselves and not part of an appearance or interior package.
