They might have carried them is the past as part of their winter package but they don't stock them anymore. Next bet is early W202 spares.
56speedster, do you have a set or are you looking for a set?
AFAIK there is an early and late style. Surf ebay.co.uk or ebay.de (or other European sites) to see the difference. 15" hubcaps from the 202 and 210 series should fit as well.
Sixto
87 300D