Hi Simon,
I do not have a Champ parts book here, but knowing the British books well, there should be an index of FV numbers in it. The FV number is in effect, the drawing number and was used in early parts lists for parts specific to that vehicle and proprietary parts were given their makers number. Not sure if the Champ part numbers were later codified in to NSN (NATO stock numbers). That explains the first line, second line is I am sure the Austin Motor Co. part number, then description and P P mean packed and preserved with a quantity of 1 in the package.
Your parts book could be an Australian one and it will be interesting to see how the parts are listed, could you scan a page so we can see what numbers they list?
regards, Richard