The 1980s were a time when all car companies did specials to help sell their lines over other makers. Chrysler was KING of this! The packages for the trucks alone was huge, so much so it baffled other makers like Chevy and Ford. Just the Dodge trucks had the Warlock, Lil Red Express, and the Macho seires pickups. And there were a few more obscure or even lesser known packages that included mostly just a set of pinstripes, or striping and interior options not available on standard trucks.
A few were like the Top Hand series and Top Kick series. And they even did up some semi to very customized vans as well. With everything from fender flares and exterior custome paint, to bubble windows and full on ******* wagon interiors.
As I said, Dodge was KING of these custom packages.
However, Something as simple as just a set pf pinstripes if it didn't include a set of wheels and or interior differences like custom upholsrry, it was probably a dealer installed option, or just the dealer paying some local company to spruce up their trucks on their lot to make them more appealing to buyers than the next dealer trucks down the street. Yours looks like one of those. If you know which delaer originally sold the truck, you may be able to go there or call there and ask if they did this in the 80s and or 90s.
There was a dealer here who sold Oldsmobiles. Since the only things not really selling to younger kids was Olds, he got the idea to stick custom wheels on the Cutlass 2 door models, and have a local painter paint what was for the times a cool custom but different paint job on every one of them. It worked for about 4 years and he sold a LOT of Cutlass Supremes and Cutlass S cars to teenagers and 20 somethings here in Albuquerque.