I did that already, its in your quote, where its still wrong, but later on i will post a screenshot of my USB Stick how the structure is and how it worked, if this helps. I am not at home currently.
One hint for all where it does not work.
For my Samsung TV I had to change the name of the file userwidget/emby.tmg to userwidget.tmg and put this file into the root folder. Than the installation went fine.