The weight was very similar to several other "upright flower" designs that are usually attributed to Salvador Ysart as often they share features that tie in well with the "3D Butterfly" weights which are also believed to be by Salvador, as opposed to other folk at Ysart Brothers (Vasart) works.
Both rows of canes in the eBay example matched those of a type used in most of the weights with a (probably Salvador) "Y" cane. It looked a bit odd that there was a space in one of the cane rows, though!
However, some similar "Upright Flower" weights were also made in either the Vasart Ltd years or at Strathearn, but the ones I have seen - and checked under UV light - have been smaller than magnum size.