I am not sure what the trim looks like on the original rig in question, but for others who have older AS and Argosy trailers, I read a great tip on one of the posts a while ago about how to come up with replacement trim in various colors and textures. That post suggested taking vertical venetian blind slats, which are available at window covering speciality shops, and cutting them down to fit the trim metal holder. By curving them with your fingers, they snap right in and are just the right thickness.
I had some white vinyl vertical blind material in the basement, and went down and got it out. I cut it carefully into long strips and it works just great! Inland has some original plastic trim insert for bathrooms in the older rigs, but it is only available in one size, and is kind of an off white. it is also $1.75 a foot!
I was able to make pieces up to 3" wide to re cover the faux walnut trim on my original lights in the Argosys I have. Also made some thinner to cover the same overdone wood look in the trim around the lights and kitchen exhaust fan. When I do my counter tops I plan to use it for the edge trim, which currently is the same metal channel with faux walnut inserts.
It is a great way to freshen up the interior of your AS at minimal cost, and with lots of patterns and colors available. One of the best ideas I have stolen from the Forums.