why mess around with all that linkage. Just go to the hardware store. gets your self a couple stainless steel bag buckles with lock hasp-cut the hasp section off and rivet to the upper edge of the main body of the bag. now fire up your dremel and carve a slot in the lid so the hasp can slide through. Now just lock it with whatever lock you want to use. And to make it all clean looking, head on over to the hardware section and look for some CUP style drawer pulls, you can get them in chrome. just screw this onto your lid over the slot you made. not only does it cover the slot, but it also hides the lock and gives you a handle to lift the lid by.