Is very keen to have one repair the chest (6)
I believe the answer is:
itches
'is very keen to' is the definition.
I can't judge whether this defines the answer.
'one repair the chest' is the wordplay.
'one' becomes 'i' (Roman numeral).
'repair' indicates an anagram (letters are fixed or repaired).
'chest' anagrammed gives 'tches'.
'i'+'tches'='ITCHES'
'have' acts as a link.
Can you help me to learn more?
(Other definitions for itches that I've seen before include "They need to be scratched" , "They're in need of a scratch" , "Has uncomfortable tingling sensation" , "Tingles as skin may" , "causes irritation" .)