@Wjbender:
there is one other file that possibly could help you, the .$$m file that is created on .wmp level compilation. it contains all the model and terrain data required for their placement, and also level block geometry data. But if you need model and terrain mesh or vertex data, it is not okay.
The model & terrain part is described in the contributions section by Emre. I use his code for .wmb compilation in my own editor. As I know it is not officially documented.