I've already suggested coming off prepay but they have no credit history so might get refused.
I still don't understand how this separate fixed payment to the council for off peak heating when the meter does not have any off peak consumption register on it.
I have a friend who just been allocated a semi sheltered council flat. it is one equipped with pull cords to summon assistance but not with a Warden on site.
The heating is storage radiators and the council charge a flat rate for heating all year round so I assume this is un metered.
That is a bespoke mounting flange. I'd look for a suitable capacitor start and run 1/2hp B14 (face mount) motor then cannibalise the old motor taking the front plate and fix to the new motor.
You might have to take off the connector box holding the capacitors and mount it nearby if there is not...
To cut steel you need around 100 feet per second, wood cutting will need in the region of 3000 FPS
An inverter will not give you 30:1 range alone without motor overheating problems and possibly too little torque to boot.
You will need to be able to drop the speed by say 4 or 5:1 by mechanical...
Fix the C2s then ask the spark who failed it for a quote to bring it up to his RCD requirement and ask the other sparkies for a price for an fresh EICR on the understanding that an RCD will not be needed. compare and contrast etc.
I have a vaguely similar installation. Power incomer and meter in a shed in the corner of the field and 300m or so of SWA to the house but all on my land (no public roadway involved).
There is a 100mA time delayed RCD upstream of the SWA and normal 30mA fast RCD in the house.