'than some' doesn't work. :( What about 'than any other (dress) in her possession?2. She had on the dress that I used to admire more than any in her possession - a light blue one trimmed prettily with lace.
than any --> than some
Shouldn't 'unkempt' be 'unkept'?3. His face unshaven, his coat torn, and no shoes, he presented a very unkempt appearance.
no shoes --> shoeless :D
BE (i.e. were) can be omitted in that context, so I'm not sure what the error is exactly.5. I thought that the music was good and the performers graceful; nevertheless, the concert was considerably longer than I expected it to be.
the performers graceful --> the performers were graceful
All the best, :D