This lovely photograph is taken from a tweet by Helen Day who runs the collectors’ site
http://www.ladybirdflyawayhome.com/
The thing that struck was not just the nostalgia of the Ladybird Books, which were a fixture in every 1960s primary school classroom of my childhood, but the subjects.
These include the series on “People at Work” (The Roadmakers, The Fireman, The Farmer, The Ship Builders) and “Public Services” (Electricity, Water Supply).
Obviously things change, and one of the interesting features that Helen Day sometimes shows is how Ladybird books did so too, for example, the elimination of smoking and the desirability of safety measures such seatbelts and lifejackets where appropriate.
However, the respect afforded to working people and their occupations, and the need to teach children about the value of utilities and public goods now seems like a feature of a lost age; especially so as Ladybird Books were so ubiquitous in the primary schools of period..
Edit: This is also interesting and perceptive (and I remember Bentalls – just)
https://barbarakafka.wordpress.com/2015/05/30/ladybird-by-design-at-the-de-la-warr-pavilion/
Planet Pedro! 
I loved Ladybird books as a youngster growing up in the early 70s – I devoured the Key Words books before I went to school (I think I amazed my reception class teacher by asking for 6a!). As you say, the People at Work series was a big part of learning about the world around us.
I’m looking forward to sharing and reading these all over again with Michael….