Hey David,
How much did they charge you to replace the bulbs? If it's not that significant, I might as well go ahead and change the bulbs at the dealer, Instead of messing with it. I was talking to someone else, who had a w140, and some of the bulbs in that cluster were on the PC board, and thus you pretty much had to dismantle the whole thing to get to it. Sounds like a royal pain, so it may be well worth it to have a dealer do it.

Best wishes and take care,
George Androulakis