I've had Barbini lamps and vases that date from at least the mid-late 1970s with the plastic label, and the transparent SVdA on pieces also signed Albarelli, which puts them somewhere between 1976-1992, if I recall correctly.
Transparent labels weren't entirely novel during these periods - I think Riihimäki, and certainly Iittala, were using them in the 1960s.