Peter Ludfords Diamond B Sport is part of the Clubmans test in 1978 by Derek Bell.

Doesn't Phil Bisgrove still have the Diamond or did it sell ?

this may help too https://clubmans.org.uk/classicfiles/oldsite/Driver%20Profiles/Profiles/northen_10.htm
and this https://racecarsdirect.com/Advert/Details/85355/diamond-r6-classic-clubman