Hello Jon,
While checking my work for exercise 4-2-1 of Music Composition 101 (page 63 of the workbook), I noticed that you used the vii°7 chord in minor progression.
https://pasteboard.co/Htwp2H7.png
However, this is not indicated in the chord progression chart
https://pasteboard.co/HtwpEue.png
Can you use 7th chords for the 7th scale degree? Does this apply also to major?