Id Cover for the back part... For temporary you could use a thinner peice of cardboard and tape it to it. Or just use duct tape... And if you are worried about it being sticky... You can use Blue Painters tape... They also make Delicate Surface Blue Painters tape.... I'm fairly sure they make other colors too.
You might be able to use one of the backs off a Tama-Go... But I don't own one... ETC... So ya.