Here are a few thoughts, without being able to see the bulbs:
The W5W could be a few things, MB uses 5 watt "push and twist" bulbs for a few applications, most common is the single-filament tail light bulbs, they also use a 5 watt "capsule" type bulb for license plate lamps. The T4W may be the push-in type bulb they use on the front side marker bulbs on cars with side markers on the bumper, such as the 210 chassis. I believe this is a 4 watt bulb, and in the US I think it's called a 198 bulb, may be incorrect, it is a 3 digit number though.
The H6W I believe is the small halogen bulb that is used for front parking lights on the newer models, this would be like the small inner oval lights on the 210 chassis, but just the bulb for the dim light when the brights aren't on.