Havn't got any pic's, but basically I have no pipe's connected to the pre-heat set-up.
As you've seen, there's a 'trap door' at the back of the airbox where that heater ducting pipe would connect up too.
The trap door is actuated by engine vacuum, which is dependant on outside air temp, if you remove all hose's from the set-up, the trap door simply doesn't open.
EDIT: Here's a good page on how the system works in cold weather
7. Digifant II Fuel Injection - 7.2 Cold Start and Cold Running Enrichment - Intake Air Preheat System
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