First a technological update - The code that drives this site is available for free on GitHub. I've just merged in a rather complex change to create proper shelfmark sorting, fixing things like numbers-stored-as-strings and handling roman numerals. Two problems yet unfixed are Fonds P.I.O, with the middle "I" reading as a roman numeral, and Arch.Cap.S.Pietro where sub-set "I" is read as roman 1 and everything gets confused.
In addition, three more smaller databases have been added to aid in the auto-labelling of manuscripts. MMMO, for Gregorian Chant, DIAMM, for early Polyphonic music and DBBE for Byzantine Greek manuscripts.
As for manuscripts, they have added 35 this week. Of interest is Vat.lat.10350.pt.A (see recto to the right), a printed diagram from 1590 showing the footprint of Old St. Peters, as well as some other monuments that were taken down, in relationship to the current St. Peters. It is most likely from a copy of The Theater that was Rome, prepared by Natale Bonifacio from drawings by Tiberius Alpharanus.