The earliest this particular edition could have been released was 1970, as that is the year that Polydor's 7-digit catalogue numbering came into effect (as did sister company Phonogram's). I am very surprised that Polydor released this, as the Dot label was distributed by EMI UK (along with parent label Paramount) up until 1974/75. I can't tell who Dot's Italian distributor was from any of the entries in 45cat, but it was probably EMI, because the sole Paramount entry for Italy (1971) is through EMI.
harry1958: further curiosity: the (p) 1966 date it bears is the year before the merkin dot label original is 33catted for. . . (vide sub.)
(the contour lps cover, as opposed to the dot lps & contour labels, only claims mono, enhanced for stereo" - which does seem rather more likely, for both - but doesn't state whether this was a pro-forma rechannelling of mono-minus-treble one side, mono-plus-boosted-treble t'other; or whether it was a technical step or three up from this, possibly separating out some instruments to either side, by referring to the original tapes. some 33catter out there may know, or be able to check. . .)