Hi!
I took my equipment to the Philippines. I stuffed the housing between my BC and the wetsuit. It survived ;-) I took out the bulbs from the video lights and stuffed them at the bottom of the case.
Recently, I bought a nice soft bag that fits the carry-on size regulations. It might get a bit heavier though. Practicing to smile when carrying helps. It holds the housing, battery tanks, lights and ports.
For the camera and the lenses I've got a "fisherman's jacket" (bags all over the place). This gives me the extra 4-5 kg I need 'cause all you have mounted to your body doesn't count as extra weight ;-)
I made my way to the Sudan without any troubles and losses.
First they were a bit suspicious but when I told them that it's an uw-camera they gave up ;-) I haven't got a flash arm (just a flexible chain of plastic tubes for the lights) so I don't know if it's recognized as a lethal weapon. It will survive the transport checked-in anyway.
What I realized was an interesting fact: a lethal weapon is a piece that is somewhat larger in size, maybe pointy, or - simply - strange looking. I had to check-in my screwdriver bits (less than 20mm/1") but next to me a woman was allowed to carry her extensible skiing rods (which serve as a nice pointy weapon ;-) but are well known and widely regarded as harmless.
My advice: try to separate the sensitive parts and put them in the carry-on luggage. If it hasn't got a very pointy or cutting edge you should be able to argue. Plan some extra time (approx. 30-45 minites) to be on the safe side.
If it doesn' t help, there's always a nice bottle from the duty free sale you may break and use as a handy weapon ...
Helge ;-)=)