Ultimate Conclusion on Stairway To Heaven / Taurus songs origins.

   The ultimate conclusion on the Stairway To Heaven / Taurus songs and their origins are the same origins. Sheet music from a church song. 
   Both songs have an origin from the same sheet music. A particular church with a Christian Church congregation. 
  I suppose the music that came from the church, originally, was a song that was sung in that church. The sheet music, for piano, without the lyrics was most likely the framework that was emulated and used as a guideline to form the like sounding melodies. 
   The exact sheet music is not known, now, but it may come out in the future that the exact sheet music will be known.