Two weeks have passed, and something you,
Konstantin, did not give further details. So we have to answer you, just from the one that is. Generally, such problems are referred to as your "to extract information from data gaps, they are by no means trivial, and their decisions are purely probabilistic nature - with a probability often much less than 100%
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The signature on your picture resembles (but not 100%but) the signature of the Italo-American artist Toyetti Virgilio (Virgilio Tojetti, 1851 - 1901). Until 1870 he lived in Italy, then immigrated to the United States.