Complex sentence: Reference: replacing earlier models made of paper covered pasteboard, sheet metal, wood and more recently aluminum; boards designed as foldable wallets, originally made of leather, are still used, primarily in England, but are now generally made of pliable plastic.
Split into simpler sentences: Reference: replacing earlier models made of paper covered pasteboard, sheet metal, wood and more recently aluminum. Boards designed as foldable wallets, originally made of leather, primarily used in England, are now generally made of pliable plastic.