Thats really cool.
It reminds me of one of my favorite books. Kindof old but still very useful.
"How to Hide Almost Anything"
http://www.amazon.com/exec/obidos/AS...lthackerorg-20
It starts out small. Places to hide a ring, or a few bucks. Various excellent ideas on hollow items, or compartments you can add to furniture. Then it moves up to safes size. Then how to do secret closets, secret rooms, etc. Then it starts getting crazy. How to hide a car, a house, a corporation, a country.
A very fun book to read (besides being very useful)
If the guy was still doing it I would send your thing to him as a suggestion for his next book. How to hide a manufacturing plant.
Gandalf Parker