My very fat vintage Filofax I snagged on eBay along with some pretty charms. This is a vintage model called the Filofax Cavendish with 30mm rings in the personal size which is
Filofax Brown Personal Cuban
Philofaxy: Van der Spek Standard with 30mm rings - Overview
Filofax Standard Ring Binders A5 A6-personal Pocket Mini and - Etsy