Found that Bernard Scouse air box quickly ;-)
Ha ha I wish! I been trying for nearly a year to find one. I think I go the Reverie route but expensive!!
As far as I'm aware (and I stand to be corrected!) the Bernard Scouse airbox is designed for the Jenvey DTH TBs, for the Caterham roller barrel versions you'll need the Caterham R500 or Reverie Silverstone airbox.
Caterham and Lotus Seven Club Leadership Team Member
The register for all numbered limited-edition Caterhams ....... www.thecaterhamregister.net ...... www.instagram.com/thecaterhamregister
The Bernard Scouse carbon airbox fitted fine to my KR500 on its roller barrels
Orange is my new black