Crossword Puzzle Instrument of Marxism?

Clue: Instrument of Marxism?

Online store offering (APP with 3 letters)
Treat offensively (ABUSE with 5 letters)
Publican's offerings (ALES with 4 letters)
Famed office (OVAL with 4 letters)
Police department officer (LIEUTENANT-2 with 12 letters)
He had a whole family of musical instruments named after him (ADOLPHESAX with 10 letters)
Purvis' instrument (UKE with 3 letters)
Bank offering, informally (REFI with 4 letters)
Quickly, in the office (ASAP with 4 letters)
Art supplies from an office supply store? (STAPLESPASTELS with 14 letters)