These plates at light switch and heat/ventilation levers on dash were factory fitted to US Pagodas only (e.g those that have code SA491 on body data plate).
See also this thread: https://www.sl113.org/forums/index.php?topic=29161.msg210898#msg210898
Hi Barry - If I am reading your stable list correctly your Pagoda is a 1966 230SL. I can tell you that even the U.S. spec '66 230SL did not have those plates. U.S. DOT safety and labeling regulations went into effect for the U.S. 1968 model year, so the earliest U.S. spec Pagoda with satin finish horn ring, thicker dash padding, soft door pockets, etc., would be a late U.S. spec 250SL. Some of the safety and labeling regulations were phased in. For instance, while side marker lights and front seat shoulder belts were required for 1968 model year vehicles, front seat headrests did not become mandatory until the 1969 model year. When the headlamp and defroster labels were phased in would be and interesting subject for exploration.
My guess is that most folks who acquired a 280SL from the States and subsequently changed out the round headlamps for Euro lamps, deleted the side marker lights and maybe even went back to hard door pockets, probably left the light switch and defroster labels intact. Their presence on the dash would be a dead giveaway to a knowledgeable observer that a car that otherwise appears to be a home market pagoda was actually originally a U.S. market car.
