Congrats on your 1st MB ,i imagine you are over exited etc and want to fix /change /add to the car wich is perfectly normal & a good thing but since the car is black on black i would'nt install a black grille ,i think it takes away the beautifull front of the 140 ,if however you like the black grill & the way the car looks later then might as well add the smoked black headlights & blinkers as well ,instant nightrider look without the gadjets ,there is only one question there ,"Do you like the nightrider look or w140 look now do you " ,lol .
Black grill yes but with the chromed fins on it looks best (look below),now imagine the cars look below with the grill you would like to add to it
All you need to get are the HID 6000K set lights from ebay,they produce the same light like a late model w221 merc .
On e'bay (again) for a black car with clear headlights there are blinkers available in diamond crystal look ,they look cool i think or the rarer double half coloured once wich are half clear & about a quarter orange ,those were my favourites .
Here you go & happy modding hopefully the outcome will be like picture'd below .
The only part i would change on the car below would be the corner blinkers ,the once fitted are the dull blinkers lens ,this one needs the crystall look blinkers to match the headlights same goes for the side blinker on the fender , another modification i would strongly look into would be the mirrors with the blinker in them ,available for late models but not early once .