Have you tried Target
Last winter for Christmas I bought my daughter sheets for her bed. Flamingo's and "Silver" Trailers with Christmas lights, I think made by "Nick and Nora". For summer they had Flamingos and bbq's, which are now her summer sheets. For those that like them, they might go nice with some of your interiors.
We just purchased and a 24ft Argosy, twin beds, and I think she is planning to move them out there when we go in trips. At 13,she is already planning on how "We" should redo the interior of the trailer. What is it with women and wanting to re-do things all the time?