Keir,
I can see a few problems off-hand.
Why weren't the studs sawn or ground off to make them shorter?.
I agree with you on the part about the size of the busbars and the fact that the connections could have been better distributed along the bars.
630mm2 would suggest to me Aluminium cables, were AL/CU lugs used in the connections?.
All I seem to see is Tinned Copper lugs a la Utilux.
Are there washers under them nuts?, like shake-proof or the like?.
Are only half of them MCB's on or were they installed up-side down?.
