Thanks for your thoughts, Anita!
I really don't know about the Seguso label on that bowl

They sell lots of fine Murano glass, with sometimes surprising (well, to me) labels / signatures; but I don't know enough about what Seguso Vd'A may have produced in the 1950s (apart from Flavio Poli Sommerso pieces)
My Mazzega bowl and its label look very 1970s to me, but I couldn't find much on the net regarding their output of decorative glass (vases, bowls, etc).
The idea seems to be the same in both pieces, but the execution is a little different -- mine looks "crisper" (and more attractive if I may say so

)
Michael