Well I bought a set of 1900 Davies knobs from THONK to act as replacements.The pots on the MCB are 6mm D shaped shafts, so they fit perfectly and it now looks GREAT...
Apart from the fact that all the indicators are in the WRONG places!

DOH!
The knobs on the MCB have the indicator at 90 degrees to the D shape. Which is quite unusual...
