class radplus {
    file { "$radplus_archive":; }
}

class radplus::ver2004 inherits radplus {
    $radplus_archive = "/var/tmp/radplus_2004_linux_i586.tar"
}

# JJM I'm not entirely sure how to reference the source archive
#     in an abstract way, yet...  perhaps the visitor pattern?
class radplus::ver2006 inherits radplus {
    $radplus_archive = "/var/tmp/radplus_2006_01_00_0101_linux_i586.tar"
}