Possible Clues:

• Part of a footnote abbr.
• Op ___ (in the work cited)
• Op. ___ (in the work cited)
• Camp apprentice, for short
• Footnote abbr., op. ___
• One of the townspeople (Abbr.)
• Camp supervisor-to-be, briefly
• Inhabitant (Abbr.)
• Op. --. (where mentioned)
• No gentleman, once taking nervous action the wrong way