(1) It shall not be lawful for any person to drive a large public service vehicle while such vehicle is being used to carry passengers for reward unless he holds a driver's licence then in force licensing him to drive a public service vehicle of any kind.
(2) It shall not be lawful for any person to drive a small public service vehicle while such vehicle is being used to carry passengers for reward unless he holds either a driver's licence then in force licensing him to drive a public service vehicle of any kind or a driver's licence then in force licensing him to drive a small public service vehicle only.
(3) If any person drives a public service vehicle in contravention of this section such person and also the owner of such vehicle shall each be guilty of an offence under this section and shall on summary conviction thereof be liable, in the case of a first offence, to a fine not exceeding twenty pounds and, in the case of a second or any subsequent offence, to a fine not exceed