I can't post links but I found the story of this car, #B139BG:
It was in this form:
"Beutler had bodied one 1947 Bentley Mark VI as a dhc. Ernst Beutler-Kueng did inform that the Bentley Mark VI originally had been built for a Swiss customer who didn't give permission for any photo of the car to be shown. For decades Beutler-Kueng kept in a ‘Confidential File’ a few mono-photos that had been taken taken with great caution without the owner's knowledge just prior to handing over the car. The mono-photos show this 1st body by Beutler on the chassis of Bentley Mark VI, #B139BG. The quality of the more than 50 years old mono-photos isn’t perfect, but these might well be the only photos available worldwide that show this particular car."