this is a small but useful Peter Francis website whichis of some help.

Furness (1902) reported that Chinese merchants sent a Lukuk Sekala to Europe to be imitated. The Kayans weren't fooled.

http://www.thebeadsite.com/bbhl-01.html

his talking about the circle red-yellow decorated black bead, same on coin coin necklace..(which is not rare in Borneo).