I am not good on St Mande weights, but some features in this one do seem to line up well with illustrations shown in George N. Kulles's Identifying Antique Paperweights - The Less Familiar
On page 55, he shows a cane which he calls, "Eyeglass" (having a connecting rod on two double-convex lenses) and on page 56 he shows, "Twin Ovals" (two oval-shaped bullseye canes set together) and "Pinched Bullseye" (single bullseye cane pnched together in the centre).
Looks to me as though the centre element of the dark-blue cane in the outer row is "two bullseye canes set together with a connecting rod". This seems to combine the connector of the "eyeglass" with the "twin ovals" that Kulles has identified.
Add to that the "chunky tubes" (my description) in all of the canes and I would say that St Mande could be right, according to the information so far known.
Leni said (more or less):
... Two St Mande ... UV tested together ... it was clear they were probably NOT from the same glasshouse!
Well, yes. And, no. The two weights did show a different UV result. But that might just mean that a different glass batch was used rather than they were from a different glasshouse - although that could still be the case. Until people have tested lots
of these type of weights, we cannot really be certain of anything based on UV results alone.
On UV results, I like to pass on an interesting occurrence from 2005. At a Sotheby's auction there was as a "rare Pantin Clover" weight. It was stated that the UV reaction was identical to other Pantin weights tested in that way. In reality, the weight was a fairly well-known Paul Ysart Clover, not a Pantin. The glass used for both early PY (1930s to c1960) and for Pantin weights (19th century) shows pretty much the same reaction under UV! It always needs more than a UV check to determine an attribution