Chap seeking to probe apprentice's financial record (6,4)
I believe the answer is:
cheque stub
'financial record' is the definition.
(I know that cheque stub is a type of financial record)
'chap seeking to probe apprentice's' is the wordplay.
'chap' becomes 'he'.
'seeking' becomes 'quest' (synonyms).
'to probe' is an insertion indicator (probe can mean to poke or prod into).
'apprentice' becomes 'cub' (I've seen this in another clue).
'he'+'quest'='hequest'
'hequest' inserted within 'cub' is 'CHEQUE STUB'.
(Other definitions for cheque stub that I've seen before include "Record of a bill of payment" , "remainder of payment?" , "Payment counterfoil" .)