I stubled onto two things while trying to model buildings:

1) The UVW of the .item files isn't properly editable with the Unwrap UVW modifier. My own explanation is that the multiple materials used on the model cause this problem.

2) I can't really use them in the game, because I need to regenerate the descr_items.db once I want to put it in, but the txt files as is aren't capable of doing this. Anyone has experience with this? Maybe editing the file by hand, or with a tool?