I used diffrerent sources, Anita, and came to different conclusions. Lutz was specialist in lampwork, reticello, filigrana, millefiori and "candy-striped" glass - one of the few specialists in the US. His work is very much influenced by the Saint Louis style where he had his training before emigrating. His productive life in the US spanned from 1860 to 1904 - so there are plenty of examples in various musea around the country. In the Saint Louis style, quality is everything and unfinished pontils are unheard of.
The finger bowls we are discussing here do not ressemble his style, but are pure Venetian - from the colour, thinwalled form with optical effects, aventurine trim, the shape of the foot it is obvious that the glassmaker had a Muranese training, not a Saint Louis one.
The Sheldon Barr attribution still stands. Salviati had 2 factories in Murano (one Smalti, one blown) glass, British financiers and retail outlets in Venice and London. There must have been quite a production at the time. He also sold products from other Muranese glass blowers in his shops.