Ich ruf zu dir, Herr Jesu Christ

When you search on IMSLP for an anonymous choral prelude to "Ich ruf zu dir, Herr Jesu Christ", you won't find the two pieces from Neumeister's manuscript I uploaded yesterday and the day before that. However, you do find an intruiging piece of organ music (https://imslp.org/wiki/Ich_ruf_zu_dir,_Herr_Jesu_Christ_(Anonymous)). The transcription dates back to 2005 and was part of the Mutopia project. No source for the transcription is given. I searched the internet extensively and could not find a reference to this piece other than the publication on IMSLP and the website of Mutopia. I would expect to be able to find a reference to a manuscript or to an original publication, yet nothing shows up. Where did the editor, Kilian A. Foth, find this piece? The piece is a bit uneven in that the second half of the piece is not related to the first half at all and that the overal mood of the music does not very well with the text of the chorale. Other than that, it is well written and very nice to play. Could it be that Foth wrote it himself? I'd sure like to know, or else I'd like to know the source from which he transcribed this piece.
The score on IMSLP and Mutopia has one staff for the accompaniment and one staff for the chorale melody. I think the music better readable when each hand gets its own staff. Manual changes are easily indicated with roman numerals. So I made my own version of this score. An odity is the final bar of the piece: the notes are f, c and f. It sounds a bit open and out of character with the rest of the piece in my ears. So in my performance I play an a flat with the left hand.

Score available here: http://partitura.org/index.php/anonymus-ich-ruf-zu-dir-herr-jesu-christ