Check your battery connections and the voltage on it from the alternator. Voltage variations are really visible on a string of LEDs with a current limiting resistor.

Since you're in the UK you could go see Big Clive (.com UTube).

Anyone got any tips of the best way to pop out the dials. mine see to be set firmly in their sockets!

Dials?
If you are referencing Gauges, then try to reach through the trunk and push out the gas gauge first and then you can get behind the others from inside the car.

See if one of them come out easier. Take that one out first. Then you can reach in and push out the next one. If that doesn't work, use a screwdriver and a rag (so you not damage the edge) and pry careful at the ring of the gauge or dial.

Hope this helps.

Cheers
Engelbert