I too had a fuel leak near the injector pump, I replaced all of the fuel lines and fix nothing. Then found it was leaking from the "Fuel Stop Valve" when I went to replace it I foumd it was only a bad O-ring.
It has been leaking since the day I got it, but only now one friend who owns a 1999 model looked at it and told me about the recall on injector seals. He got it fixed through MB Cherryhill NJ and they changed all injector, replaced all fuel like and filters only charged for labor around $400. I will contact MB.