Old chamber ten refurbished is A1 (9)
I believe the answer is:
excellent
'a1' is the definition.
I can't judge whether this defines the answer.
'old chamber ten refurbished' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'chamber' becomes 'cell' (I've seen this before).
'refurbished' indicates anagramming the letters.
'ten' is an anagram of 'ent'.
'ex'+'cell'+'ent'='EXCELLENT'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for excellent that I've seen before include "capital" , "First-class" , "A-One" , "'Superior, first class (9)'" , "Outstanding, very good" .)