As a study guide, buy a newer version, things have evolved since 1970. You should be cognizant of the contemporary standards and expectations when you are monitoring the radiological environment of occupational workers and the general public.
As a fond piece of nostalgia,....sorry Glyn, the only ones I have from that era I keep, they are helpful when researching history files and the written ramblings from RSO's past require me to look up their references.
But,...I'll keep my eye out for one, they're usually stuck on some forgotten shelf gathering dust and turning yellow.