Looks like a well used car, doesn't it ? If I recall correctly, it belongs to an Internet User by the name of LiaMerc who was a member of topklasse at one stage. Isn't this the second time that the car has come up for sale - previously listed at about $8k. ? Anyway, it's not a 1978 model as advertised. Probably 1976, not that it matters that much. I've known of at least one 1976 model that absolutely 'howled' when you pressed the loud pedal.
As you say, Tim, it is a 450 speedometer, so it will read about 20% fast. The 5000 rev counter is correct for that model, as is the water pump that's the same as on 6.3s, albeit with a housing that looks like a 6.3 unit, but is NOT. It's a rare housing, interchanges with nothing else.
The back seat is in the usual worn out condition, yet the fronts look very good. Are they leather or MB-Tex ? They suspiciously look like the later. Under bonnet section has a well worn appearance. Regards Styria