This is okay if you have access to these files.
Somebody else reported that if you change the grading URL to end with action=grade (instead of "action=grader") this presents the old interface - this could be useful although I am unsure how safe this method is? Ideally the assignment settings would allow this switch, rather than relying on the theme fix described above it would be good to be able to choose "grade" or "grader". AND/OR ideally it would be possible to configure the default display. Currently the default is the annotation screen which is not popular with everyone and not needed in many cases.