We've had the 80mm cap fins tooled up to be exact replicas of the NOS cap purchased over the parts counter at Vasek Polak years back.
Great care was taken in measuring and duplicating this two hole fin. These are perfect for sports purpose Oel filler necks (Read: ST, 914-6/GT, R, etc.)
You will need the 80mm Blau cap to finish this project off (commonly found on the VW BBS sites).