I did an overview of the Empire and Aristocrat models know to me at http://www.typewriters.ch/blog/2014/07/empire-portable-typewriter/ .
Please refer to this page in the future. It is a blog-based part of my website, but I gradually want to shift all my contents there as it is convenient to write and update articles, and also graphically adapted for use on portable devices etc.
Entries will be almost exclusively in German, but google translate is getting better and better. So this could work.