Possible Clues:

• Perfectionist left in label
• Fussy type covers front of ledger with adhesive label
• Someone who fastidiously insists on something
• ... pedant adding line to label
• Perfectionist provided ultimately faultless puzzle
• Small chap manually catching fish, a particular type
• Head of school, teaser and martinet?
• Nit-picker
• Demanding individual senior nurses apply light touch
• Problem posed by second person insisting on detail