The decals were added in '68 when the catalogs changed from COBRA to SHELBY. The sticker was added to a production ( over the counter) Ford dual point distributor. As Bob said never used on a "production" vehicle , over the counter only. In '69 , the switch was made to the Mallory version which featured a "Shelby specific" blue cap which is very rare these days. MOST of the Mallory units had red caps and some tan. They featured the aluminum tag and "Shelby Equipped" logo on the tag. I too have a 289-302 version with the original blue cap. For $100 + shipping someone else could own it.
Randy