OK I am getting a little out of my depth here but:-
1 possibly the link I gave you will only show sfs for 430 and up.
2 Where did you put the sfs? It should go in /mnt/home otherwise boot manager won't find it. Open rox from the menu. Go up one level with the green arrow at the top left, click on mnt, click on home. This is the directory that the sfs should be in.
3 If you click on the sfs does it mount and allow you to get inside? I believe that if you mount it manually by clicking on it you can go into the sfs and click on the Open Office icons to run which ever applications you wish.
I believe that you can download and install extra languages from the Open Office site once you have Open Office running. But I haven't tried this!
I did a quick search of the forums for an Open Office for 421 but nothing came up. Perhaps someone else has more information.