found these from a google search on Doka
http://www.t4-forum.de/t4-forum/pickup/pickup.htm

http://www.t4-forum.de/t4-forum/t4gespann/gross-t3.jpg

http://www.t4-forum.de/t4-forum/t4gespann/t4-gespann1.gif

Main site in German... but intuitive enough to navigate for images.. 
http://www.t4-forum.de

all i can say is WOW
http://www.t4-forum.de/t4-forum/eigenebusse/arminkienzler/T4ZX912.jpg

is this gas cap the same as the one they put on MK1s?? 
http://sequal.drunkencomputing.de//vw/bilder/treffen/01/wietzendorf/images/P9150010.jpg