My typesetting of “Troisième livre d’orgue des huit tons de l’eglise” can be downloaded from imslp. This edition may be easier to read than the period sources, but the music has not been simplified in any way. I highly recommend finding one of the facsimile editions and studying the original publications; the rhythmic freedom of the pieces is much more apparent. Also, those editions often include extremely helpful essays in their introductions.
Feel free to post comments here about errors and other lapses.