JONJA MBOLE METAL ANKLET AFRICAN CURRENCY, COIN, CONGO, COLLECTIBLE pre-owned

Description

Offered is a giant hollow leg band / ankle bracelet / ankle currency.  When I purchased it, it was called "Jonja Mbole Ziare Hollow Leg Band Coin".  This is not my field of expertise.  I typically research extensively, but I bought this simply because I liked it, and it was quite different from anything else I owned!  Now I'm downsizing and it needs a new (bigger) home :)
I've seen similar pieces labeled as copper.  Based on some of the flecks and oxidation, I think there could be some copper, but I don't think it's pure copper.  My best guess is that it is primarily iron.  It is heavy: 4-lbs, 6-oz.
5-3/4"at the highest x about 9" wide
I have no idea how old it is.  I have found this :
A bronze Mbole currency ankle bracelet. This ornamentation was worn by the Mbole people in the democratic Republic of Congo was used as currency for major transactions or were offered to women by their husband as part of the marriage agreement and worn on their ankles.
Please ask questions as no returns are accepted.