I'm not sure, but I think the euro fog lights just use H3 bulbs like the US spec lights:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1CQ0J3JZ41VF0YE2NU&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1983&product=Y4001-14070&application=000033923