Now all sorted
To get it all properly working, it needed some more recent UK tts files, which I have managed to track down.
You now have a small selection of voices, all working.
German, 2x Lithuanian, Russian; 2x tts US, 2x UK + 1x Natural.
I'll add a link soon.
[EDIT] Link added - comments appreciated!
https://www.sugarsync.com/share/bqwypdbmtoim5