Axel Stauber has a lot of VW aircooled parts - including Types 3 and 4.
Take a look at his pages at http://shop.volkswarenhaus.de
You have to be able to get the hang of the German to see the Type 3 stuff as he hasn't done the translation, but with pictures it's not too hard.
Click on the red boxed arrow for the model (Typ 3 1500 | 1600, or Typ 4 411 | 412), then again on the sub-menus until you've seen all the bits!
Thanks to Baby Bleu in Canada for this link.