Thanks to Hypotyposes for the pointer.

Codex W, a fifth century MS (so, 400's) is one that is important for textual critics to have access to. Thanks to Beloit College, who placed scans (photos?) of Facsimile of the Washington Manuscript of The Four Gospels in the Freer Collection, the book of Mark from W is now online.

The images are of superb size and quality. The uncials are readable with some work. This should be very helpful for those interested in such things.

Also note that Codex W apparently has the longer ending of Mark.