Oh, no problem. And welcome to the forum! I just saw that this is your first post.
Yeah, vinyl material, once the surface layer starts to decompose or deteriorate, cannot be restored.
Part of my business is bus and car vinyl wraps. The high-end 'cast-coat' vinyl with overlaminate has a 5 year outdoor guarantee. I'm not sure the motorhome makers are even using 5 year vinyl for letters and graphics. Some of my emblems went south in under 5 years. At ten years now I'm looking at painting some on or having some new ones made.
For a winnebago product you can still buy original stickers but they're stupid expensive. Better to have a sign maker or bus wrap company make new ones. Even better, paint them on.