Here is something interesting ...
From the Ad:
Original 914-6, FG-Nr. 914 XXX 0134 Erstauslieferung im März 1972 nach Frankfurt
They xxed out parts of the VIN but mention the car was first registered in March of '72 in Frankfurt.
So i did some digging in the VIN database and 914.243.0134 is not listed, but 914.243.0135 is and that one also resides in Frankfurt.
Then i looked at '71 cars and again 914.143.0134 is not listed, but 914.143.0135 is and that one also resides in Frankfurt.
What are the chances of that?
My best bet at this point would be that the car is in fact 914.243.0134