It's the missing covers for the headlights that tell us it's not an earlier Series 1. The taillights above the rear bumper, among other cues, tell us it's not a Series 2. The differences between the very late Series 1 and the Series 1½ are largely mechanical, related to the first round of emissions controls applied to cars sold in the US starting with the 1968 model year.
Actually, now that I look at it, it has hexagonal wheel nuts rather than winged knock-offs, which makes me think it's a '68 Series 1½... (Winged knockoff hubs were a no-no starting in '68 according to the FMVSS.)
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