The first of these small Datsuns was the Datsun/Sunny 1000, chasis code B10.
Produced from Sept 1966 untill Dec 1969 in 4 models [1967, '68, '69 & '70]
The two cars in the picture are 1968 two door sedans. [October 1967 to September 1968] The blue one is a Standard model while the red one is a DeLuxe.
The red one [& probably both] is a very early version as it still has the 1967 model blinker lights on the side of the fender/mudguard. This was changed to a short spear shape for the definitive 1968 models.
The picture is from a sales brochure.