Sorry Mike, but 155xxxx 1600's are Voll Cabriolets. As far as I have seen, '66-67 1600 production went only as far as 153xxxx then the '68 US cars were 156xxxx. I have seen that there are 154xxxx 1600-2s but never in the US as US bound cars.
Yes the 150xxxx cars have a few very unusual detail differences, as well as the different "6 Volt" nose panels for all of the early 6 volt cars up to the end if '67 production. My 1508028 Bristol late '66 production car has all of these early details.
The differences between '67 US bound cars and rest of world 1600-2s were the sealed beam headlight buckets, US English speaking gauges. Mid 153 production the bumpers lost the license lights, lost the early skinny five slat kidney grille gaining the four slat one, gained the optional in Europe over riders and a few other minor differences. My 1530962 Granada car had the US tail panel license lights and over rider bumpers originally, it also had a factory installed US Blaupunkt Frankfurt US AM FM SW radio, and had the four slat grille. I have seen earlier US bound 153 cars that still had all the euro bumpers, the wide euro rear license plate holder and five slat grille.
Very early '68 production 156 cars still had the remote booster brakes as well as the chrome trimmed dashes and the badge above the taillight as earlier cars but gained many later details such as the later door latches as evidenced by my friends 1560847 Manila car.
HTH and Cheers,
You should know better than to challenge Mike (lol).
1500001-1550000 prod '66.3 - '68.2 - Euro 1600-2
1850001-1900000 prod '68.2 - '70.6 - Euro 1600-2
2650001-2676591 prod '70.6 - '71.3 - Euro 1600-2
1550001-1553252 prod '67.4 - '71.3 - Euro (RHD) 1600-2
1560001-1572930 prod '67.8 - '71.3 - USA 1600-2
1557001-1558682 prod '67.9 - '71.6 - Cabriolet 1600-2
HTH