So I discovered some old posts in which this was nearly figured out thanks to the simplicity of the PC version's formats. There exists a texture extractor for this game, but models are still not unraveled yet.
I have here some of the model files. Hoping someone can get a method of conversion going for them
https://www.dropbox.com/s/eoyjjj5er5sn2l1/ST11.zip?dl=0
Judging from the textures, this pack includes Sigma somewhere.