Ray,
I have no idea who in Murano made them but as Gay Taylor of Wheaton Village in Millville, NJ dates Arthur Gorham having them made there as early as the 1960s, then that's a good date to put on them.
Other Qs are; How long did they continue to make them and how many did they make?
We may never know but they do come up on ebay with some irregular regularity, if you know what I mean so they are common enough.
The original Millville article (circa 1905-1912), on the other hand, is extremely rare with only a handful known to be extant.
Millville crimp roses (circa 1905-1912), that are simply footed and do not have the stem are very very hard to find as well.
Recent sales of those have eclipsed as much as $7,500.00 USD (L. H. Selman) and I've never seen one come up on ebay.
Emil Larson, who made footed crimp roses in Vineland, NJ in the 1930s have come up on ebay only twice thus far.