Ivo is, as always, a cunning linguist, and for those of us less well educated, fazzoletto apparently, means 'handkerchief-shaped' - so do we take it that fazzolettino means 'small handkerchief-shaped'?
Size Ivo ?
According to Leslie Pina this shape was started by Venini in the late 1940's, and became one of the most popular (not iconic) designs of the 1950's - a shape which included most of the known Italian (Murano) decorative techniques - plain filigrana being possibly the most common. Have a look in Pina's 'Fifties Glass' page 184 for fazzoletto of varying styles, sizes and colour.
If this were from the 1950's, would be nice to think it might be Venini, but may have to settle for simply Murano origin, and of a more recent date of manufacture, and probably a shape made by a variety of factories.
Sorry this doesn't really help, but perhaps a clue in here somewhere