James,
It's getting more difficult to find the euro light parts seperately in the USA. When I was shopping last year, Tom Hanson (very reliable MB dealer parts man) said MB wasn't shipping just the parts in anymore. You shouldn't have a hard time finding a whole assembly, but you'll have to call around to find individual reflectors. I ended up buying a slightly used set of reflectors from VanDijk in The Netherlands. Shipping wasn't as much as I expected and they were easy to deal with (in English!) through e-mail. I swapped them out in my housings and everything's great!
Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both tops
1994 E420