Without knowing the uv results, both longwave and shortwave, it is not possible to be sure in which years this weight may have been made. The grinding to the base could suggest Ysart Brothers or Vasart Ltd as the main candidates.
The canes are all what I refer to as "early Ysart". But even that description is a general one meaning "made either in the Ysart Brothers years or pre-war".
For a concentric millefiori weight without any distinctive feature such as a "Y" cane or a lampwork butterfly (or one or more of the many so-called "Salvador Ysart canes") it is difficult to know whether or not it might have been made by Salvador Ysart.