I tried searching for "sterling silver washer" and got some hits for these charms - a good laugh! But using the term "washer" has gotten me some "close" sterling disks that might be close enough.

In machine parts jargon, a 3 mm washer has a 3 mm hole in the center (plus some tiny bit of clearance) but looking for the proper size (for a size #0 bolt) stainless washer might be an option if I can't find it in sterling.

I can find vintage rosaries that use this type of disk & chain construction, but that would mean paying a lot (usually $40+) and destroying an intact rosary.

I'm watching auctions for broken rosary parts but it would be nice to find this disk bead by itself instead of adding to my "salvage pile" of old beads & findings.

Thanks for your help!