In 2007, just over a century after Domenico Comparetti published a photographic facsimile of the Venetus A manuscript (Homeri Ilias cum scholiis. Codex venetus A, Marcianus 454 phototypice editus, Leiden: 1901), the Homer Multitext project published new digital photography of the manuscript. The text of the manuscript is, literally, more legible from the digital images than from the manuscript itself, and far clearer than in Comparetti's volume.
At the recent CHS Summer Workshop, however, we were reminded of the continuing value of Comparetti's facsimile. Participants compared the copy of Comparetti in the library at the Center for Hellenic Studies with the digital images of a folio they had edited. The scholia were dauntingly dim and small in Comparetti, but first one team, then another noticed that external scholia they had not seen in the digital images were visible in the 1901 reproduction. In a brief library session, examples surfaced on folio 68 recto (noted by Kathleen O'Connor and Melissa Browne), 76 recto (Tucker Hannah and Leah Elder) and 79 recto (Melanie Steinhardt and Katie Phillips).
In the past hundred years, the minute notes at the extreme edge of the manuscript's folios have evidently been particularly susceptible to fading and damage. Comparetti's publication gives us a chance to recover readings no longer preserved on the manuscript.
The external scholia often consist of a single word or short phrase. T.W. Allen suggested that they reflect an unparalleled editing process in three “reprises” (T. W. Allen, “On the Composition of Some Greek Manuscripts,” Journal of Philology 26  161-181). Their proposed “corrections” to the Venetus A text may often reflect genuine Homeric multiforms, and are potentially more precious than their brevity might suggest.
One more addition to the list of projects waiting for a volunteer.