I'm sure someone else can help more but try to copy the look and feel class and make its location in say the content navigation. If you get that done you will at least be able to use the new class by adding that type of item in the content area (like adding an Article). You could then place it in a non-standard Section to keep it from the wrong users. Not sure if you can do a similar thing with the Global settings form.
you can copy the Global Ini Settings class from a fresh 3.5.1 installation or create it manually.
The next step ist create the Objekt. Put in a non-standard Section to keep it from the wrong users.
Now you should adjust the design/admin/templates/parts/setup/menu.tpl Look at the second line with the Global Setting
The url /content/edit/xxxx should be fixed. xxx is the object id!
