I uploaded this piece 10 days ago. Forum member Adri pointed out that the three repeated f's in bar 28 are probably wrong, and should instead read f-g-f. In that way the fugue theme is properly stated. In examining the manuscript again, I saw that I had overlooked three notes in the tenor voice in the same bar.
I already indicated a possible error in the manuscript in bar 35. Adri thought there might be another solution than the one I chose in the score. So, perhaps when he has time to look into it after his holidays, there is reason to make yet another version of the score.