Hi,
First off, well done. These are only small corrections.
I would harmonise bar 5 (and its repetition) as V7, as the c natural is an unaccented passing note. The main chordal note is the B (V), I think. However, remember to indicate that the d is sharp if you want to keep it as d diminished, and to add the 7th. At bar 22 I'm not sure whether you placed the "i" on beat 2. That is where I think it should go. Bar 24: iv (beat 1) V (beat 2). The first bar of the coda is I7 (1st quaver) iv (2nd quaver). I wouldn't harmonise the up-beat e. In bar 30 I think the last two quavers should be ivo7 and #iio7.
Apart from that, I see no faults in this.
Carlos R.