JHN,
This type of thing (automatic engine shutoff) is commonplace in aerospace, though typically it is related to failure of the electronic engine control system and the engine is commanded to idle, not shutoff. However, for LSR, simple system architecture for engine shutoff due to discrete parameters such as the loss of engine oil pressure, can easily be made with sensors, wires and relays.
I recommend you sketch out the architecture you want (which sensor signals causing engine shutoff), and anyone you trust with basic electronics knowledge can then sketch you the wiring diagram of how to easily accomplish it. In other words, make your own black box to do exactly what you want.
Hope to see you in a few weeks.