Possible Clues:

• British saying about mechanic, for instance
• During the boom, a non-drinker is never tops
• For the teetotaller in the barrier, see 8 down
• This part in the play would never be the top of the bill (6)
• Rear foot
• He could never be top of the bill in Shakespeare's Dream. He comes lower
• Quark's flavour, crowd round, eating too much
• Not top of the bill in a play within a play
• Pants over anything so low
• The least important seat