Irish Ferries have recently updated their SailRail section and it now includes an alphabetical list of all British stations by zone from Dublin Ferryport.
It also includes a comprehensive timetable for the Route 53B bus; Heuston/Busáras - Ferryport.
The current brochure should by now be available in the leaflet rack at many railway stations (the 2009 issue was stocked at Heuston, Connolly and other stations).
http://www.irishferries.com/fares-of...ares-sail&rail