The Header Image for the Centre for Manuscript's website is taken from page 9 of Joyce's 'Finnegans Wake' Notebook VI.B.15:

This image is reproduced with permission from the Estate of James Joyce, and The Poetry/Rare Books Collection, SUNY, Buffalo, N.Y. 
© 1977, the Estate of James Joyce, and the State University of New York at Buffalo 
All quotations from James Joyce's manuscripts are copyrighted by the Estate of James Joyce