Though this composition starts as a Trio, the Trio-like texture is not maintained in the course of the piece. There are several sports where the composer resorts to chordlike writing. It is one of the reason to doubt the authorship of Johann Sebastian Bach.
Joachim Scheufele-Leidig took it upon him to create a version of this composition in strict Trio writing. In doing so he changed the harmonic function of the choral melody as well. In BWV Anh II 64 the choral melody serves as bass voice. In Scheufele-Leidig's version the chorale melody has become the middle voice.
The result is very convincing and perhaps even better than the original. And since he made the score available I could have a go at it. And so can any organist who is looking for something new and fresh to play in the Christmas period. In my performance I changed some notes in to avoid six-four chords.