Howard,
The Super-Bebo Beborex caliper listed in the 1963 RonKit Catalogue with the "leverage amplifier" device is shown in "The Data Book" (Rebour) as a 1952 innovation. Unfortunately the book's illustration is small and much less clear than the catalogue listing.
For anyone curious about the 1963 price comparison, naturally in OLD British coin (shillings/pence) prices were:
Beborex Super... 53/6 Mafac Racer... 68/9, Mafac Top 63... 75/- Weinmann 999... 65/-
Cheers!
Bob Hanson, Albuquerque, New Mexico, USA