The critical wiring in the Mainline is already shielded for this purpose. (See the CAT5 cabling and the STP cabling that distributes power) Also, the tube socket shields keep the most sensitive bits covered up.
The rest of the wiring is fairly short or presents such a low impedance to RF that it's not all that helpful.
Another consideration is what your sources of EMI might be, and how close they'd be to the Mainline. If you have a desktop computer close by, inspect the case to ensure that it is largely metal and enclosed.
Without a whole lot of trouble, an aluminum bottom plate could be fabricated to add an EMI barrier, but you would need to add a lot of ventilation.
-PB