I think it's not possible to extract the data from Chasm.
With the viewer are just the first two models to see, the lizard and the knight. All others have a different format in the color gamma, some sort of customization.
After trying out the older programs, I don't think that a clear 3d file could be extracted, or a more efficient coder should have a try. Most are still available under the dos box, but had a dos extender to an older command.com.
So I made an example of the dino by using the viewer. A bit of foul texture, but a good looking Turok. First model I suceeded in a split UV filter.
lizard