i believe the files for actual scenes are in M&B/CommonRes/ and are in .brf format (which is as stated above, armagan's creation)
looking through module_scenes.py, it seems each is divided into two parts, which must each be buried in various .brf files, a 'mesh' and a 'body'
at the moment there are all of five scenes:
sargoth_square (zendar in the native game)
arena (zendar arena)
small_tavern (happy boar in zendar)
thirsty_lion (almost every indoor scene in native game)
encounter_spot (appears to be the scene shown at top left when in conversation)
the only hole in this that i see is the four ways in, which seems to have its buildings hardcoded in with its name
in the mob i am doing right now, i have all my towns work like zendar in the native game, except that they are all empty so far
i did a little experimenting with the four ways inn, and copying the module_scenes.py entry for four ways inn for one of my cities will create the inn scene
but if i change the scene id of it, and none of the rest, the buildings disappear and only the landscape is left