If it would look better (strickly your choice), a piece of white or black 1/2 or 3/8 inch plastic (I "think" they call it Starboard) could also make a nice panel backing. In addition to drawing a diagram (and that is a must) take lots of pictures with your digital camera up close BEFORE you pull any wires off.
You might even want to get some masking tape and a sharpie and label each wires as you take it off.
They all look good now, but get a dozen wires off and they "all look the same!"
Irwin Citation 34