Dim Main Beam Warning Lamp

Hi, Re 88 GTI cab - suffering with a very, very dim main beam warning lamp - the blue one.  With dash lighting at max. brightness you can't see it, and on min. brightness you can just about see it.  Bulbs in instrument display have been changed to the 2w versions, bulbs for the warnng lights - indicators, lights etc incl. the main beam are unchanged.

Been through the following earths:

Dash to rocker
Rocker to bulkhead
All earths connected to "rosette" above fuse board
Earth from steering column to bulkhead
Earths for rear lights inside boot
All connectors for front lights cleaned and checked
Bulb spade terminals cleaned

Someone has mentioned before on this site that there's a "rosette" behind the headlamps - if this is anything like the one above the fuseboard then its a circular multi wire connector that allows several earths to terminate to the bodywork at a single point, then I don't seem to have one near the headlamps??

Any help appreciated.  Ta.