This car seems not to be finished, I don't know if it was finished ever and I doubt that it was legal to drive it officially...

This is a Mercedes 450SEL 6,9 Station Wagon "Pollmann".
Pollmann, normally known as builder of hearses built several "normal" station wagons based on a "W116"-model, but this should be the only one based on the top-model with 6,9l-engine.