E320 Evaporator
 

I have inherited a 1994 E320. I am in the process of changing the evaporator. I also think I should change the vacuum motors at the same time. I'm wondering about the heater core? I will also change the engine wiring harness as the insulation is falling apart in some areas that I can readily see. For some reason I can't remove the ashtray and therefore the centre console. I've got the radio, heater controls, and instrument panel out. Mercedes Benz sure does a good job of hiding the fasteners holding the trim, vents and everything else. I would like to know where I should purchase the parts from? Should I use genuine parts or aftermarket? There seems to be 4 aftermarket brands. The AC Delco's description is all aluminum. Can I buy an all copper one? My father in law bought this car in Oregon and had to change the bumpers and other stuff to import it into Canada. It has about 55,000 miles and I've been taking care of the maintenance for him. I haven't done much to it, oil changes, front pads and rotors, transmission oil, brake fluid and coolant. Any thoughts, suggestions or ideas will be welcomed and appreciated. I'm also having trouble with the oil level light and heater a/c blower motor. I'm hoping the last two things will clear up with the engine wiring harness. Thanks,
Craig