The legs of the spider could easily be broken off. Therefore, your bead may not be practical for usage as a slide closure. However, it would work as a cabinet or fashion piece.

Is the pea pod cast? In your first photo it appeared to be cast -which, sometimes, suggests replication -like Robert Burkett jewelry…If the pea pod is heavy and cast it would seem new to me.

If the pea pod is thin and flimsy, it may have been a form of costume jewelry for the japonaiserie market in the early 20th century. I would have to see it in person.

In any case, the legs of the spider are impractical for a functional ojime on an inro ensemble. In regard to the signature, this can be added as a selling point to reassure hesitant buyers.

I tend to ignore signatures and concentrate on the artistic merits of a piece.