If you are at the point in your restoration where you're wondering what your engine compartment looked like when it was new, then this article is for you!  All of these photos came from David Welsford's 30,000 original miles 1964 343, one that is very authentic and has been restored to original specs.  Thanks David!

The above photo shows the anti-kink wire on the oil breather hose, which joins the oil breather unit (that rounded black plastic piece that you didn't know what it was for) to the air cleaner.  As you can see, this anti-kink wire makes the tube nicely bent around the coil, so it won't get blocked and cause any nasty problems.  I couldn't find a part # for this wire in the Parts List books, so I can't say for sure it's origin.

The second photo (above) is of the spark plug wire fasteners, which serves to keep the plug wires from touching the hot engine tin.  This photo shows the left side plug wires attached to the metal stand (VW #311 905 143A) with two ivory plastic clips (VW #311 905 451) for each wire.  The metal stand is attached to the engine tin by one 8mm bolt/screw.  For the right side of the engine, the other two plug wires are held in place by an identical ivory plastic clip (VW #111 201 261) that is mounted on the oil breather unit. (1st photo to the left of the tube)

The last photo (above) depicts one of the fuel line fasteners, which keeps the fuel line from contact with the hot engine block.  If you look closely you should be able to see an aluminum clamping piece that the fuel line (from the fuel pump to the dual carb splitter) clips into from underneath.  The VW part # is 311 127 525.  The aluminum piece itself is attached to the nut securing the oil cooler.  There is also another fuel line clamp (similar aluminum design) that your probably see in the above photo.  Look in the top-center of the photo just below the carb rod.  The fuel line that comes in from the gas tank (under the pan) going to the fuel pump is the one this clamp holds onto.

If you're this far into your restoration, you're farther than most of us!  As far as finding these pieces, your best bet is to contact Bill & Steve's, BFY Obsolete Parts, or even possibly your VW dealer.