Virtually all Italian movies of that period were post-dubbed - even movies entirely in Italian where all the actors were Italian as well, and so there was no particular need to dub it. It seems to have been a fashion in Italy at that time...

A similar situation also exists with the Patrick Bach series Jack Holborn where it was shot with an English script but with actors from many different countries and so whichever version you see has some sort of dubbing - although obviously you get the best lip sync with the English dub (and Patrick did his own dubbing for the English version)...