OK - just talked with a monitor technical support rep from Happs and he said that the first connector is used for switching between VGA/CGA inputs and for interfacing with other dedicated PCB's that may use a JAMMA connector or their own connector, so from the signal standpoint, the VGA DB15 is all that is required.
As far as the power is concerned, it looks like you nailed it Ken - the monitor is powered on at all times electricity flows to it meaning that there is no power switch provisions on the monitor itself, so it's up to me to provide a switch/relay for it.
Thanks!