I had a great experience having my Pagoda serviced at Mercedes of Alexandria. Wheel balance and alignment. Before removing the tires, they first taped the rims to protect them from the pneumatic gun and handled the car with extreme TLC. Jack Lindeman is the contact person at 703-997-4890 and has a real heart for these vintage Mercedes. They sent pictures along the way as the work progressed. Price was reasonable.
However, if your car is in poor condition and has been poorly cared for, then this might be an expensive option. If that is the case, you probably want to send the car to a reputable restoration shop and have some mechanical restoration work done before sending it to the dealer