I re-fit the looky-likey motors and take the opportunity to correct the fact the props all appeared to have been running in the same direction.
The control logic we're using was likely the very first applied to quadcopters, it being most straightforward. It is no longer in common use among model drones, it being aerodynamically sub-optimal as speeds increase... racing drones therefore invariably feature 'X' frames instead of '+' types like that here. Nonetheless design of people-carrying drones is invariably a compromise, so I've pursued operational practicality and cost-efficiency over speed.
What you see in the picture is still not entirely correct as the clock-anti-clock-anti sequence seen in the inset is generally viewed from above, and this is the underside of our drone. Yet something else you learn quickly in this game is that the perfect is the enemy of the good.
We've just the look-and-feel of the electronic speed controllers (ESCs) to contrive and then this baby's good to go, for PR purposes if nothing else.