Dave van Arnam & Ted White 
Sideslip [EPUB ebook] 

One minute I was in New York . . . walking down Sixth Avenue, a private eye on a two-bit job . . . Next minute I was in New York . . . a crazy town I almost recognised — but Goebbels was speaking in Union square, Hitler invited me to a cocktail party, and aliens from outer space were running the whole show. Fun City it wasn’t . . . Plucked from his own "time", a pawn in a Galactic power play, Ron Archer fights his way through a deadly maze of intrigue and conspiracy to an incredible destiny at the end of the star lanes!