Permitted change of use 1972-1974 - Public forum - Planning Advisory Service (PAS)

I am trying to establish what changes of use would not require planning permission in 1972. I would also like to view a copy of the Town and Country Planning Act 1962. As subsequent legislation has superseded what was in force between 1972 and 1974 I am having great difficulty and would be very grateful if someone could advise me where to look. Please send helpful suggestions to heidi.wade@cbre.com Many thanks Heidi