I recently bought a 380 SE for $500 . I bought it to wreck for parts and as I was driving it home I realized it was gem. it's an ex Japan (no emissions gear) 99,000 original miles,blue leather interior,Metallic torquoise green ,and it's so clean underneath, the cad plating on the bolts look like new . I'm going to use it as a daily driver because it's so good. If it were left hand drive I would advertise it in Germany where "young timer Classic W126's " are appreciated and sought after .
So,If your friends car is that clean with the ALL IMPORTANT service history, you could try advertising on Egay.de or any of the German classic car sites .