I think they just used up stock of this book from 1939 or the 1940 edition?,and glued the label with the contract information over all the other models the book covered,the later war time books have the SV engine on the cover.
Below is an unusual parts book dated 1942 for 1938 Triumph models for the Pacific Area ,apart from the covers every thing inside is the same as in the 1938 civilian version of this book.