Very interesting book........ A Ladybird book first published in 1971 and revised in 79...... The site shows the pages from both versions so you can compare the changes in diagrams and technology between 71 and 79.
Some pictures didnt render but I discovered if I clicked the box with the X on those ones,the picture then loaded.........
http://web.archive.org/web/200411140...r/default.html