Martin's Schneider weight is very likely by the American maker named Schneider.
The 1887 dated "crown" style weight first mentioned is one of a type (but probably most being regular millefiori) that were from Murano, seemingly with any requested date included. There are known examples of those types which also have a false etched Schneider signature (see thread linked to by Patrick).
The only type of "paperweight" made by the French Schneider company were produced in the 1960s and all were clear glass with air bubbles. They were produced as "Globes", rather than "paperweights" (or "presse-papier").