I don't think scaling a model non-uniformly in WED is the appropriate thing to do. When you scale a model in this manner you would end up also stretching the texture/skiin in an undesirable way. If you need your model to be scaled a specific amount along a specific axis, then open your modeling program and do it there. In fact, you can create your entire level in the modeling program to specs and then simply export the pieces and put it together in WED. Frankly, if you are using models for level geometry, then there is no real need to build or scale any of it in WED at all. Do it all in your modeling app.