Almost no rust in SoCal, but the sun can be brutal, especially over the hill in San Fernando Valley. Even a little failed clear coat on black paint really shows. Painting is tedious and thus expensive. Somebody could vinyl wrap it, but also pricey (>$2K). As you say, many want flat black and chrome-delete today.

I got about another 5 years out of the black paint on my 1985 300D by wet-sanding the failed clear-coat "skirt" w/ 1000 then 2000 grit. Inside the skirt, I scraped off the remaining clear-coat debris w/ a dull putty knife. Each time, it looked OK until an outer skirt formed. Some here said (at least my year) M-B didn't use a normal clear-base paint, but rather what could be a final coat of black, then protected with clear. The underlying black wasn't perfect, but probably because of uV damage too. Anyway looked acceptable.

So, if you spent a morning you might get shiny paint, especially if a DA-polisher like I now have. Just let prospective buyers know they might need to repeat in a few years to keep it shiny. I repainted 3 cars this summer in a home-made booth so the $70 DA was justified. My 1985 300D because I replaced half the body during a crash repair, moving over fenders, hood, and trunk from a recently-repainted 1983 salvage car , so painted that color to match, which is now a modernish grey-blue. Had left-over paint so also repainted my 1996 minivan. With that fad grey color, people do a double-take, "Look at that new cross-over, it even has a sliding door. Brilliant, got to get one."

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans