The following 25 titles, which were all originally issued between 1964 and 1974, were completely revised and re-issued from 1979 onwards.  Although the text of most of these books was left unchanged from the Vera Southgate originals, the books were completely re-illustrated by a variety of different artists and the conventional Ladybird layout (text on the left, full-page picture on the right) was abandoned.

In other words, although a book might be described as 'Ladybird, The Princess and the Pea, Vera Southgate, series 606d' there are actually two very different versions of this book - and if you remember the earlier one from childhood, you will NOT be happy with the later version:

Hopefully this gallery will help you get straight the options available.  If you want to buy a particular book, on www.ladybirdflyawayhome.com or Amazon or eBay, make sure you quote the YEAR (and maybe the cover design) to make sure you get the version you remember.  You'll find the year of publication of each book when you click on the gallery thumbnail picture.