I would take these pictures to some RV shops, show and explain the problem you have and ask what they have available. I had problems finding inside panels for our '85. No RV shop had any. Finally found something close to what we were looking for at Home Depot. Many makes and models have different sizes, patterns and colors for their panels. If RV shops don't have any maybe try a company that builds trailers and see what they have

Try this place
https://www.hemetvalleyrv.net/