Sounds like a plan! As for the extant descriptions of individual pieces, I've just been editing the article on his very best-known compositions, the two Romanian Rhapsodies and, if the state in which I found it is anything to go by, sources in English aren't worth much. (You might like to take a look at the edit history there.) For the rest, Enescu was not an ethnomusicologist (as Bartók and Kodlály were), and so it would be unreasonable to expect from him a deep knowledge of the rural folk music music of his country. It is also frequently observed that he "absorbed" folk elements into his compositional style, rather than actually quoting folksongs—with a few exceptions, mainly the two Romanian Rhapsodies. Consequently, I wouldn't get my hopes up about any great revelations about the presence of actual non-gypsy Romanian folk music in Enescu's compositions.—