Supplied OBJ totally broken, had no complementary MTL or textures. Supplied FBX called a missing texture folder. Four (4) supplied Blender files lacked documentation...
Re-exporting supplied DAE to FBX using free AutoDesk Converter failed to find any embedded textures and gave a broken model.
Re-exporting supplied FBX to OBJ/MTL using free AutoDesk Converter gave a tidy, nicely grouped mesh with few (21) bad polygons among ~200k. Sadly, the dozen MTL materials do not map any textures, most lack relevant 'toon' colours, so model appearance as-is gives poor match to product images. Should look much better after appropriate texturing...
This model is not intended for 3d printing. If you try to print, you'll get the exterior shape of the corridor. Designer was quick to respond to me though.