Help in bun proofing a cage door?

My dear bun who is 6 months has just discovered what great fun it is to gnaw the bottom part of her cage door! It's a good quality mansion she resides in and the bars of the cage is sandwiched between two thick bits of wood but she's chewed all along the bottom and starting to expose the screw and wire!

She has plenty of toys and 'proper' things to chew such as cardboard tubes and wood things but oh no she only chews what she's not suppsed to! She loves to chew her cardboard box that i put in her night bit to keep it warm for her. I've also tried a Thompson directory, but that is obviously beneath her in her opinion:roll:

A carpenter i know has suggested puttting a piece of magnolia wood -which is quite tough-to replace it but not sure if that's safe for bun. Admittedly she may be a bit bored due to the rubbish weather during the past week as this is when it started. Hurry up sun!

Does anyone have any ideas to bun proof the door a bit? I'd be very grateful for any comments

not sure if this would work but could you maybe attach a hay rack to the bars so it sort of sits over the bit she's chewing?