The crossover boards revealed fairly ordinary parts. Chinese MKP caps, ceramic resistors and an Iron cored coil in the bass filter. Better quality parts should help here, so I need to draw the circuit schematic and determine what changes will be made. The Capacitor and Resistor values are printed on the  parts, I emailed Quad UK and they were very helpful in supplying the Coil values. All parts were measured from the two boards anyway to check how close they matched the stated values, the coils were very close, some caps were and some were not, resistors were also pretty close.