The "a norma dalla legge... 1973" to my knowledge refers to a law regarding care or fabric content lables and just menas to say it conforms to this law from 1973. So unfortunately it's not much of a help for dating, except that it can't date from before that year.
Those care symbols look kind of old though, so I think it's probably before 1990s. Therefore 1973 to roughly late 80s. I think it looks 80s.
