I finished testing and I consider the German translation as final. See post
http://binarylegends.net/forum/index.php/topic,981.msg8383.html#msg8383 for the translation files.
Some points:
1. The problem with the font shadow at the bonus screen remains, I replaced the German special character 'ß' with 'ss' and the shadow keeps being misaligned. The translation file looks good (I 'diffed' it with the origin New.trs)
2. When trying to start the old demo with the language changed to the translation, AGS complains:
An error has occurred. Please contact the game author for support, as this is likely to be a scripting error and not a bug in AGS.
(ACI version 3.4.1.15)
Error: Failed to read translation file: GER.tra:
The translation file is not compatible with this game. The translation is designed for 'Indiana Jones and the relic of the viking'.
This most propably is because the old demo is a separate .ags file and expects their own translation file.
3. Bonus Screen need a little adjustment in AGS editor, otherwise two text lines overlap slightly. The screenshot shows my old translation, ishortened it but it still neews two lines. The only thing I can do with one line is a very short "Glückwunsch zum Abschluss!" (Congrats for finshing!)
The GUI adjustment in AGS:
GUI's -> gui -> title screen -> 40:gBonus
Element 'Label27 (Label; ID1)', change the 'Top' value from the layout property to '42'.
This is how it looks like without the adjustment