Those indeed are the first 6 characters of a Euro-spec W124 chassis VIN. The format is different for US models-in your case likely WDBEA36 etc.
Tell them it's a US car-I hope this helps
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car