Crossword Puzzle Some office stamps

Clue: Some office stamps

Post office, vis-a-vis stamps (ISSUER with 6 letters)
Office stamps (DATERS with 6 letters)
Mil. post office (APO with 3 letters)
Phone no. at the office (EXT with 3 letters)
Office rate: Abbr. (WPM with 3 letters)
Exterminate the bugs in Arthur Sulzberger, Jr.'s office? (SMITETIMESMITES with 15 letters)
Gunnery officer's concern (RANGE with 5 letters)
Title for a senior officer (COMMANDANT with 10 letters)
Somersaults in the air (FLIPS with 5 letters)
W.W. II British officer Orde _____ (WINGATE with 7 letters)