By chance while searching on Google Books, I came across a study of Titus’ work. I learned from this that an unpublished French translation of books 1 and 2 existed (I have written to the translator and asked for a copy) and a century-old unpublished German translation of book 4 and part of book 3. I wish that the work were online in English, or at least an English version of the existing translations.
Returning to the Nitrian desert finds, I also stumbled across a statement that after these were brought to the UK, the Assistant Keeper of Manuscripts, William Cureton, reserved all the most interesting finds for himself (!). This forced scholars to work on other parts of the vast collection of texts, with good results. It is depressing to think that those who control the national collection, now as then, treat it as if it exists mainly for the benefit of its staff and not the nation; special rates for reproductions, refusal of any photography except by themselves, limited access, etc. Nor is the BL alone in this, I would guess.