When you add textures to a ship in 3ds max, you use what is called the Material Editor. For SFC1, each material would only consist of a regular texture bitmap file, but for SFC2 and 3, each material would consist of a regular texture bitmap file and (usually) a self-illumination map, which is a bitmap that adds specularity to areas of the regular texture bitmap. In order to properly convert a ship from SFC2 or 3 to SFC1, you need to remove the self-illumination maps from the materials in the Material Editor.