From memory the Gtn was a S1 with the alpina. it was more or less the last push before the factory made the fedralized model for the usa wider with the stainless side vents these were nearly all shipped to the states.They did make at least one series3 squinty headlights and swept up boot in metallic red i remember seeing it in dispatch and a couple of years later at Newton motors.The series 2 being the rarest of production runs. The Gtn i drove at the factory had a hard top and was told it was a bit of a faff to swap and droned a bit but that could have been me not used to the side pipes. Hindsight is a wonderfull thing as it was within budget at the time and only about 4k difference in price. Em