Hello - Not sure of your reasons for suggesting Venetian - to me it appears to have had its origins more probably in Czechoslovakia, some time around the 1930 - 1950 period - perhaps a little earlier possibly. The shape is typical of that period, and the gold banding is a common decorative feature on pieces from that area - they are often very heavily banded with gilt - sometimes parts of the glass have a frosted effect, and the glass can be other than clear. This might possibly be part of a cocktail set. I believe these are mould blown, which accounts for the flat base - the top rim may well be ground/polished, and possibly beveled.
However, the surface patterning (birds etc.) is all wheel engraved (the word etching is used only if a wet acid process is involved) - and different sized wheels achieve different effects/depths. Worth remembering that not all engraved pieces started life decorated thus - in some instances wheel engraving is known to have been applied later.
I don't get the impression these pieces were ever backstamped - they were made very commonly and only if you're lucky do you rarely find a label still intact.
