A Ham Tin was used as it was about the right shape to fit in there. It performs the function of providing somewhere for the engine case breather tubes to connect to the intake suction (VWs need lots of crankcase ventilation). The breathers once went to the air cleaner but as the oil fumes from the engine condensed they built up in the bottom of the air cleaner and then dripped onto the exhaust pipe and everywhere else. The plus side of this was that the air cleaner foam element was always nice and oily to catch the grit well. Anyway now the breathers enter the ham tin and the fumes condense there and drain out when the engine stops through a small bore tube like a battery breather. This means a small patch of oil when the bike stops but no smoke clouds and burning oil smells while riding. I don't think of the small patch as a Leak. It's sort of like the bike marking it's territory like a dog.

A Flour Sifter was used as an air cleaner case as it was about the right size and had a wire mesh grate part way along it.
The bottom was blanked off and a hole connects to a hose to the Ham Tin.
The flap at the inlet end is for cold weather. It can be closed to make the air intake from around the exhaust pipe below it.

Well you all know the problems involved in clamping off the fuel tank balance hose when taking the tank off.
This little plastic clamp is used in hospitals on Enema sets and very nicley cuts off the tube for tank removal.

The Up, Over, Down and Under style exhaust was developed because the rider needs somewhere to put his feet.
The rear exhaust ports come out right where the feet are. Both rear ports join over the top of the gearbox and then go back behind and under the gearbox to join a balance pipe between the pipes from the two front cylinders. Seems to work.

The Gearbox Adapter is a ring of 1cm thick aluminium welded straight to the front of the gearbox. This is OK as the gearbox does not split either vertically or horizontally. The gears are removed through the front of the box.

The Deep Fryer Temperature Gauge is a simple solution to knowing how hot the various bits of the engine are getting.
It can be placed where concerns are to see what happens. It usually sits around 300F and the VW people tell me not to let it get above 400F.

The Oil Heated Manifold is a neat trick which I can't see why Dr Porche didn't do in the first place. It solves 2 problems.
VWs are notorious for Icing up the carbie in all but hot weather so it needs a heat source.
Also the oil gets quite hot in an air cooled engine and if cooled can help keep everything else cool.
The feeds to and from the original oil cooler simply feed through a jacket around the inlet manifold and back again.