Scirocco Register

the pic below is of an 8v and a 16v injector. top is 8v and bottom 16v

8v has a thinner cup with tighter thread, around 8 threads
16v has a wider cup and wider spaced thread, around 5 threads

I think the 16v ones are the same as early 8v ones

my storm had the wider thread, but a different style to the 2 in your picture .
https://www.google.co.uk/search?q=golf+ ... RrhKAkulM:

vw at their best then