For Heaven's sake don't say i told you so...

Careless Talk costs Lives

Since these Illustrations date to WW2 and since there is a lot of variation in the lettering (3 different 'e's 4 's's etc.) I think it's safe to say these are hand lettered by Fougasse.
http://www.original-political-cartoon.com/gallery/artist/fougasse-kenneth-bird-1887-1965_29.html