These have been described as custom made
Were described by a person from art of venice murano glass gallery museum as classic murano technique.
and vey well made
they do have pontil on base and inside of cup
comment was made :
"The decor of the stem's decoration gives it all away: these are four memories of Venezia. The decoration remind me of the decoration on the prow of a gondola. The black of the applied decoration evokes the colour of the gondola as well"
Would appreciate further info
thanks Bill