My TT has a sticker on the outside near the water heater and there is another one inside the coach on the backside of a cupboard door. Maybe a more detailed search could reveal it.
If you still can't find it, send Jayco an e-mail or worst case you'd have to apply for a new one from the Secretary of State.
2006 23B Hybrid with 10k round bar WDH
2011 F150 4x4 SCREW Ecoboost, Max Tow, Integrated TBC, 3.73 LS axle, Firestone Ride Rite airbags.