The anonymous piece posted two days ago, turns out to be (probably) from Johann Ludwig Krebs. Martin Moree pointed out to me that both the libraries of Leipzig and of Berlin own a manuscript, containing this piece. The manuscript in Leipzig attributes it to Johann Sebastian Bach, the manuscript in Berlin to Johann Ludwig Krebs. The latter attribution seems the more likely one. The manuscript in Leipzig has the last bars missing, the manuscript in Berlin has a complete piece. In both manuscripts the piece is in e minor, instead of f minor as in the transcription available on IMSLP (and Mutopia). There are quite a lot of other differences as well, not in the least a different ending to the piece. I withdraw therefore the f minor version, and publish this version, as it is based on a far more authorative source.
A curious fact I missed in my previous post, is that the accompaniment in the second half of the piece is based on the first phrase of the melody to the chorale “Aus tiefer Noth, ruf ich zu dir”.
The recording was done with the sample set of the Silbermann organ of the Stadtkirche Zöblitz by Prospectum.