If you are satisfied by the Medicea version, you can simply use the Directorium chori. However I don't know exactly the differences between pre-1911 und post-1911 Breviary, so be watchful for differences. Also, you could use the Liber hymnarius or this Scribd document.
They can be found as well in Sandhofe's Nocturnale Romanum (webpage in German). If you are settling for a medicean version, you can also try the Music of the Sarum Office. @Protasius: your links do not seem to work... PS - The Music of the Sarum Office webpage has versions which are not medicean, but medieval, as used in England for the Sarum Rite. It's better than medicean-like stuff, though often different from more ancient sources.
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