The wiring harness is the same on all M104 W124's, irregardless if it's a coupe, sedan, or wagon.
If you purchase it here on PartsShop, I believe it's about $550.
Give Phil a call on the 800 number tomorrow morning.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".