"[...] I think you'll have to explain which war."
There have been many wars since 1945 - so the term "pre-war" does depend on context. In the context of the 1960s it presumed the then recent WW2 - but I wouldn't have been surprised if the tents were actually 1914-18 vintage surplus.
I remember a white-haired form master talking to the class about being a submariner "in the war". As an 11 year old I innocently asked "which war?" - as he looked much older than my parents and older cousins generation who had been on active service in WW2. His comment was something like "Cheeky imp!".