3Where a dwelling is or forms part of a hereditament for which no gross value was shown in the valuation list on 13th November 1963 (including cases where any gross value so shown is to be disregarded under paragraph 2 of this Schedule) section 56 of this Act and paragraph 1 of this Schedule shall have effect in relation to the dwelling as if for the references to that date there were substituted references to the first subsequent date on which a gross value for that hereditament was shown in the valuation list.