Lars and Peter working to improve state of wall (9)

I believe the answer is:

replaster

'to improve state of wall' is the definition.
(to replaster is to plaster a wall again)

'lars and peter working' is the wordplay.
'and' means one lot of letters go next to another (I've seen this in other clues).
'working' is an anagram indicator.
'lars' after 'peter' is 'peterlars'.
'peterlars' is an anagram of 'REPLASTER'.

I've seen this clue in The Independent.

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