The Zephyr was the only modern Vibroplex made on a three-inch base. Basically a Zephyr is a Champion on a three-inch base with a circuit closer. Marketing-wise, the Zephyr is a bit of a puzzle. The added circuit closer pushed up the cost, so a Zephyr cost about as much as an Original. Most people decided to just go ahead and buy the Original, so Zephyrs are fairly scarce these days.
Zephyrs originally came with the standard black crackle finish, and later came with the standard gray crackle finish. That’s it. The Zephyr was discontinued in the mid-Fifties, making it the shortest-lived modern Vibroplex.