John And Paul Go To School

There's a book which is called "John and Paul go to school" ( see picture number 1). My brother used it when he was 7( it says on the cover that it's for children in 2nd grade). The author of the book is called D.H Howe. The book was illustrated by Paddy Mounter.
When we look at the cover of the book, we see two boys going to school. I have noticed that the one boy looks like John Lennon and the other one looks like Paul McCartney( they have the Beatles haircut and their faces remind me of the two Beatles). Do they remind you of John and Paul too?( see picture number 2). I think that's why the title mentions these two names. Picture number 3 is a photo from the inside of the book.