I've ordered both parts just in case although the thermistor limits the surge of current when I switch it on which sounds more like the issue I'm experiencing.
The MOV protects from power spikes and surges.
I've also lost some illumination in the lower playfield...I hope I haven't damaged the bridge rectifier or capacitor 
Maybe that is what their job is BUT Thermistors almost always go high or open circuit and MOVs almost always go low resistance or short circuit.
It's a good idea to replace them both anyway.
