100% finished now! What a great puzzle for Christmas! It took a while to work out how to draw the 3D cube but got there in the end and it enabled me to solve my last face to face clue by seeing what options were left.
Got a full grid, but baffled by 2 face-to-face clues:-
2: Student abandons study to do Xmas post perhaps?
6: For Uncle Sam, face of special animal in the stable