I would call FR again, tell them what the dealer said and see if that is the real story...Maybe the dealer just doesn't want to mess with it. I recently purchased several replacement decals for my SOB direct from my manufacturer. Another possibility is, if they really don't have any that are usable, perhaps there is on from a newer model that is available..
2015 Chev Silverado 3500 dually D/A
2016 Cedar Creek 36CK
B&W Patriot 18K, Trail-Aire pinbox,
Level up, dual panes & all that stuff...