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Mercedes Benz Parts & Accessories - Mercedes 123 - 1977-85 E CLASS
Scroll down- Euro light lenses are at the bottom. Very sorry this happened to you. I have Bosch Euro headlights I bought from them about 6 years ago, and they are very high quality.
However, if you order from them, make SURE it is the same brand, and will fit. I have read that they are very picky about accepting returns. This may or may not be true.
Also consider putting on some of the clear plastic shatter-proof lens covers that are peel and stick- I did this when I got my set- they do not alter the appearance. I got mine from Griot's garage- very high quality- covered with a hard outer layer of acrylic; worth the investment. These lens covers might not have stood up to the damage done to your car, but are at least pretty good protection against rock chips.
Post a pic when you get a replacement installed ! EDIT: Have you tried turning on the headlights? If the actual bulbs themselves are broken, the replacment bulbs are H4 bulbs, which are fairly widely available. They plug in from the back of the reflector. Package instructions say don't touch the glass on the bulb- if you do, remove fingerprint oil with alcohol or whatever solvent it takes. Hella seems to be a good brand.