If you're interested in a Zephyr, why not shop around for an NJS frame? You can get them in a lot of funky sizes since most are custom.
Just search by seat tube size and look at the pics...it's easy to spot the frames with the longer top tubes.

Quick example....
https://www.njs-export.com/collectio...-metallic-52cm
56cm top tube/52cm seat tube.