agree, very interesting, but regret no positive idea as to maker other than suggesting Lalique. They often created large ball-shaped stoppers in order to show some creative moulding etc., and sometimes these had added colour - I think fish were among the motifs they used. Failing which one of the other French makers of decorative bottles - either scent of booze - from the early deco period perhaps. Take it there aren't any matching Nos. on the stubs?
sorry this is a bit lacking in helpful information.