9. In section 28 of that Act (restoration of lapsed patents) for subsection (3) there shall be substituted—
“(3) If the comptroller is satisfied that the failure of the proprietor of the patent—
(a)to pay the renewal fee within the prescribed period; or
(b)to pay that fee and any prescribed additional fee within the period of six months immediately following the end of that period,
was unintentional, the comptroller shall by order restore the patent on payment of any unpaid renewal fee and any prescribed additional fee.”.