A51.dll does nothing, it was probably drm at some point, not loaded into the assembly can be removed entirely.
models are stored in multiple strips of vertexes: verX, verY, verZ CONN, where the vertexes are 4byte floating points and CONN could be either 00 00 00 00 or 00 80 00 00, or 20 00 00 00. 00 80 00 00 always comes in pairs of two.
The vertexes are connected in triplets for every vertex except for when 00 80 00 00 occur in the last of the three consequent vertexes.
Stored as .NMP (Appearntly)
Mixture of RAW data and Mp3, RAW data being used for mostly everything.
Precompiled shaders
Stored as .xbmp. See tools for method of conversion/back