If you can't find gaskets to seal your Type 34's headlights to the body (VW Part number 341 941 191 A, part 49 in the diagram above) you can make your own.
This circular seal prevents water from getting into the headlight bucket, which can lead to serious rust. The gasket is the same for both sealed beam and non-sealed beam headlights.
While the diagram above specifies a 4mm thickness, the original gasket is actually only measures 4mm at its thickest point and tapers to 1mm at the outer edge. If all you can find is flat sheet rubber for your gaskets there may be some trial and error involved in finding the right thickness to achieve a good seal.
When you place your gasket on the car you will notice that it will cover some screw holes and alignment holes. Carefully notch the inner edge of the gasket to clear these holes. Try to remove as little rubber as possible (see below).
A good source for sheet rubber is McMaster-Carr Supply Company.