The ALIAS nurbs file is made of hundreds of small patches, with no human logic in their structure. Trying to modify it is just pointless. And creating a whole new regular nurbs model would be too long. The MAYA polygon object has a too high vertices density to be modified. Trying to fix the topology mistakes responsible of the nurbs flaws will just add new issues.
At the moment, it's getting clear that the only way to clean the surfaces ( and save the project...) is by acting on the original low polygon working object, before it has been smoothed and turned to a high density polygon.
We issue a request to AIRBUS to obtain this strategic file.

In the meantime, thanks to BLENDER's animation functions, I check all the kinematics: seat, shelf, armrests, screen and I find that nothing work properly. There's some interferences between the seat and the surrounding parts when it's shifted to horizontal position. Interferences too between the armrest and its base when moved to its lower position. The tablet sliding direction is slightly wrong and it needs more room to ensure a good functioning. The screen is supposed to tilt, but there's some interferences too.

After 2 fruitless attempts, I get the right MAYA low poly file. Then, the actual modeling job can start.

Moreover, some areas and functions haven't been well defined. The small armrest beside the storage needs solid hinges. Its shape has to be redrawn.
The panel beside the footwell is too thin.
AIRBUS also asks for some last minute design refinements.

Eventually I would have to remodel almost everything.

Without the power of polygons, it would have been just impossible in the time allowed.