I just got myself a SlimCD-Rom to try this conversion myself :-) will post step by step pictures to show the conversion.
My other case conversion is currently getting uploaded here:
http://www.silibil.com/case/I have 3 Amiga1200s Im gonna play with. One goes in the HiFi case. The other gets the SlimCD the other im not too sure yet. :-D will be fun. The forth stays home with me.
@Cycloid
Dude do you have any decent step by step info like Gutjahr's page? I cant see clearly how u did urs. Would be nice to see different ways of converting. Cheers m8