So I have a box in the clamps as we speak. Just need to affix a couple of hinges, the rest of the top, install the lock, do up an edge treatment so opening the box isn't a hassle, and maybe apply a coat of oil, and I have a rough draft of a locking knife box. It's not pretty, but given that I have a Sunday deadline and other child-proofing tasks still outstanding/in-progress, it will do. If you'd heard all the cuss-words that spewed forth last night, well...we'll leave it at that.
So about those larger knives... I ended up using angled blocks - with embedded magnets - glued to the underside of the fixed portion of the top. The magnets are powerful enough to let my largest chef's knife hang freely with the box standing upright, and when flat only the heel touches the bottom. For the smaller knives, they have their own slots.
I have pics so far, but am waiting to try and wrap it up tonight or tomorrow morning.
And again, thanks for your well-wishes. The second home-study is Sunday, and then who knows what hoops lie ahead after that.