I understand the desire for a stock appearance, but I like to use that area for storage. I built a custom oak box for that area so that I could store what I wanted back there, rather than use a store bought box, which have fixed compartments. I have a lot of stuff back there, from jumper cables to spare v belts, oil, tools, tie down straps, etc.
Here are some ideas:
http://67-72chevytrucks.com/vboard/s...t=seat+storage