For the 737 Combi, How did changing the proportions of the passenger vs cargo areas work? I am very interested in the 737 combi models and want to learn more about how they worked in practice. For the 737 Combi, How did changing the proportions of the passenger vs cargo areas work?


I have read that regulations require passenger areas to be maintained
at higher pressures than cargo areas in order to prevent potential
fumes from reaching the passengers- is that true? If so, how does
that work in terms of the air pack design and other aspects of the cabin air design? 
Could operators change
back and forth the proportion of floorspace that they dedicated to
cargo vs passengers, or was it semi-permanently fixed? If it could be
changed in normal operations, about how long did it take or how many
man hours?
Could the bulkhead between the passenger and cargo areas
be located at any point inside the aircraft ("infinitely variable
bulkhead location" you might say) or were there a certain number of
fixed points that the bulkhead could be positioned?
For 737 combis
operated in a 100% passenger configuration, what did the cabin look
like next to the door? Was the cargo door basically fully finished as
though it was any other part of the cabin, or was it more industrial
looking/louder/colder?
The Boeing 737QC (Quick Change) is a Boeing 737-200 which featured a 134 in × 87 in (340 cm × 221 cm) freight door just behind the cockpit. The floor was strengthened and allowed for palletized seating for faster configuration changes between cargo and passenger flights. A switch using a system designed by Falcon Aviation in Sweden allowed the seats to be removed in 20 minutes. Each seat row would roll forward to the cargo door, then slide out into a container for storage. The container would be rolled away and cargo loaded into the space where the seats used to occupy.

The video below shows how the conversion system created by Falcon worked.


                
            

Good luck creating a toy hauler.