Evening gents, I'm the Andy Rowlands Mr Jedi was referring to. I posted all the pics, of which these are a selection, in a thread in the General Modelling section, entitled Alien Nostromo interior models, a few days ago, with detailed descriptions of which scenes they represent in the movie. Please feel free to have a look and comment if you like. To answer the scale question; they weren't built to any particular scale, the passageways are about four inches high.