I know they were available for all Trucks F1- F8 in 1952. I have an accessories brochure with that printed in there as a Factory accessory. But I believe earlier as well. Perhaps as far back as 48 but Im not exactly sure. I also believe they were made by Signal Stat in Brooklyn NY. Not sure of the date but these were produced for a long time. Again guessing but I believe until the late sixties. As you can find them in really nice condition. Not sure how long Ford offered them as OEM. But they were around for awhile.