Account book found by shelf on right (6)
I believe the answer is:
ledger
'account book' is the definition.
(synonyms)
'shelf on right' is the wordplay.
'shelf' becomes 'ledge' (synonyms).
'on' is a charade indicator (letters next to each other).
'right' becomes 'r' (common abbreviation).
'ledge'+'r'='LEDGER'
'found by' acts as a link.
(Other definitions for ledger that I've seen before include "Heath -, Australian actor" , "Book for keeping financial accounts" , "record-holder" , "Old-fashioned heavy accounts book" , "Accounting journal" .)