A few years ago, David Irvine of Team Bentley Spotting posted about a Rolls-Royce Corniche Saloon converted to Bentley specification:
Further investigation on the excellent rrsilvershadow.com
website identifies it as chassis #CRH21998, the factory development car for dashboard and air-conditioning updates introduced on the 1976 "Corniche 1A" and then fitted to the revised 1977 model year and later cars.
However, there is more...
A Brooks Monaco auction catalogue from 1997 describes #CRH21998 as ex-Monteverdi Car Collection - the museum of Peter Monteverdi, founder of Monteverdi Automobile and a Swiss Rolls-Royce, Bentley and Ferrari distributor.
Below is a scan from the catalogue where it's described as being painted grey with a beige leather interior:
It certainly looks very different now...