Andrew Barker has published "The Institution as E-Textbook Publisher" in Insights: the UKSG Journal.
Here's an excerpt:
Providing students with sufficient copies of core textbooks is an increasing challenge in an age of ever higher fees, economic realities and heightened student expectations regarding provision of library resources. This article outlines the partnership between the University of Liverpool Library and Liverpool University Press (LUP), which has progressed from the creation of a library advisory board to the co-creation of two bespoke and open access (OA) e-textbooks as part of a Jisc-funded project. It tells the story of why we have gone down this route at Liverpool and what we hope to gain from the creation of these e-textbooks.