Hi Brendan,
Your 'O' is correct.
Men = OR (other ranks) + (on) short time = T/ engaged in (getting inside of) work = PLY (as in, to work - verb)= P(or)+(t)LY
PORTLY = Def, Corporation
A corporation is (apart from a company or firm) a beer belly or pot belly- hence, Prtly.
Your clue for RASCAL gets it's 'as' part from the word 'when' in the clue (As and when)