I spot a difference with European Opel Rekords: there are tiny round lights on both side sof the grille, next to the indicators. Parking lights I presume. Opel USA publicity photos always show this colour, perhaps the only car they had for these purposes?
Opel Admiral 1967 calendar This was the cover of the 1967 calendar. Opel never gave any information about the location of the cover photos, but this car is also portrayed on a photo that is taken in Unken, Salzburgerland in Austria.