I would like you to investigate all the manuscripts of Prokofiev to see just how many pieces he wrote for harp. Don Henry once hinted to me that there was another one yet unpublished, so he must have seen it somewhere.
You could write a thesis about the Concerto for Harp by Boris Tishchenko.
You could write a thesis about the Russian elements in the Concerto for Harp by Nicolai Berezowsky.
You could search for other historic harp music in the libraries. You could write about the symbolic role of the harp in Tchaikovsky’s ballets, operas and symphonic music.
You could write about the influence of the Party on the lives of harpists in the early 20th century, how they were affected by the Revolution, or the lives they lived under