Fraggle, the book says bumpers and wheels are cloud white L581 on bays 68-70. (its the front badge colour too)
Early deluxe bays have Black L41 wheels and early ambulances had Ivory L567 coloured bumpers.
71 and on bays had pastel white L90D bumpers and badge with chrome wheels.
No emoticon for yawning, Shame. :wink: