The Challenger R/T-SE had a "formal roof" with a fiberglass plug that contained a smaller rear window. It also came with a leather interior and ceiling console. It had it's own VIN sequence that differentiated it from the regular Challengers: JS23 was an R/T hardtop, JS27 was an R/T convertible and JS29 was an R/T-SE hardtop. 442W30 is correct, there was never an R/T-SE convertible built. You could order an R/T convertible with the leather interior, but that did not make it an R/T-SE.
If you want to know about R/T-SE Chargers, I can tell you a whole bunch more about them