OK, I think I will have to answer my own question here - the lesson learned being "never assume things work as configured". :)
After re-thinking everything, the most logical assumption was that for some reason, the configured keymap was not being used. Checked the logs from the last reboot and yes, there was a line
keytable: Loading keymap: failed. Looked at the
/etc/init.d/keytable script and used the same command as in there, just without error redirection:
[root@server root]# loadkeys et
unknown keysym `currency'
/lib/kbd/keymaps/i386/qwerty/et.kmap.gz:5: parse error
syntax error in map file
key bindings not changed
So, the estonian keymap which came with the distro's console-tools package turned out to be faulty. The keyboard used in that case was in
/etc/sysconfig/console/default.kmap, which was french (the server came from France originally). Seemingly, someone had tried to change the console keymap but never checked whether it actually worked (and done so on all 4 blades).
As the physical keyboard was actually swedish, I tried
loadkeys se-latin1, which gave no errors. For changing the layout, CentOS/Redhat has a simple tool called
kbdconfig, which changes
/etc/sysconfig/keyboard and also copies the right keymap to
/etc/sysconfig/console/default.kmap (but did not issue any warnings about the 'et' keymap). I will check weather the keyboard works as expected when I get to the datacenter next week.
Bonus question: How can I find out the keymap currently being used by the Linux console?