The third violin sonata is certainly a much more mature and characteristic work than the first two, but it is less frequently performed and recorded.
This recent thesis has the third violin sonata as its subject:
And other relevant theses:
Violin and piano
Villa-Lobos, Heitor. 1953. Troisième sonate = Terceira sonata : pour violon et piano. Paris: M. Eschig. This score may be available through Interlibrary Loan from your local public library.
This is a rarely played work.