I picked this up today and it was being advertised as an Opio Tenor. It is definitely a soprano and I can't find any markings on it to indicate any model # or Opio anywhere. There was a warranty card tucked away in the case but instead of a model # it just listed all of their main line models, but didn't even mention Opio in the card. The label inside also says made in Hawaii. Any idea what this one is?