Sorry to hijack the thread, but that sort of makes sense to me.
On the early EU cars as per the photo with Lukas, you have to manually select, via the top of the air filter housing, winter (rear of engine near exhaust) or summer setting (inlet from front of car). The Oz version is probably because you never have low enough temps to warrant the two positions. On the dommorello car it has the temp controlled intake which automatically should switch from rear to the front according to the temp of the inlet air? This system was used on all facelift carb cars AFAIK.
Peter