The European Voter is available from GESIS (German Social Science Infrastructure Services) It provides free access to subsets of data on elections and voting trends from ICORE National Election studies in Denmark, Germany, Great Britain, the Netherlands, Norway and Sweden with many covering the 1960s-1990s. These subsets served as bases for the analyses published in Jacques Thomassen (ed.) "The European Voter" Oxford University Press in September 2005. The database includes integrated files, trends, study descriptions and other relevant documentation.
The European Voter Database can be accessed via the CodebookExplorer Internet Version. You have first to register for a free account.