It is going to be a tight fit, but I think I will be able to fit all the electronics. I have been designing a custom circuit board that will bolt into the body cavity of the omni.
So far it will have super bright SMD leds, a internal sound module and .5 watt speaker. A selector switch on the side that allows you to choose from red or green. A momentary switch on the plunger button that activates a swoosh sound. There will be room on the sound module for other effects, and I might offer a option of a extra switch for those who want added sounds.
The lid will be connected to a internal bar that spans in the distance between the lid ears and rotates a internal arm. I have not decided yet, but I am thinking a magnetic reed switch will be used at this location, and the rotating internal bar will hold a magnet that rotates into activation position when the lid is opened. I am also considering a dampened rotating switch that activates power, and gives the lid a bit more drag when opening it. The only problem is the body compartment is limited in space and most dampened switches are too big.
Ill post internal images when I have a better mock up.