Little precision, on Exclusive auto sales, it is actually Called Chander Auto repair, same phone number and the address to get there is 245 10th avenue (at 24th street).
I discovered another one which is specialised in Jaguar and Rolls Royce, but has 1 guy doing Mercedes (they service many antique cars, such as XKE, etc) at 73 street and York which could be an good option. A friend of mine had some body work done on a Porsche there and was very happy:
Sports and Classics
517 east 73rd
212 288 01 73
Fabrice
Silver 1971 280 SL
New York City