LEPTA is in Chambers under the singular form 'lepton'. The point about the pairings is not that they're associated with one another in terms of having a same or similar meaning, but that taken together, they are a precise definition (supported by Chambers) of the unclued anagrams.
thanks bathtub.
I realised early on that the pairings wern't neceassrily 'linked' but was struggling to find the correct 'perfect' associations as you indicate for the last two pairs. I also forgot that Chambers often does not not have plural defs listed independently.
incidently any thoughts on why PRANK for the title other than mischevious in nature?
I guess because Prank = pleat, another anagram of the word to be shaded. The same definition (prank3 in Chambers) also gives 'to set in order' - and of course it's Dumpynose's practical joke at our expense.