I've been communicating with Vern for a future article and asked him the questions you've posed here about the Ensign, and I quote:
"The photo at Nivelles when the Ensign was still green was taken during testing and before I did the Belgium GP. The car hadn't qualified in any races at all at that point. I should have finished 7th or 8th in the GP but had to pit with fuel pickup problem.
"Teddy Yip and I were driving to Silverstone in my orange Maserati Merak (not a Lambo)"
Vern wasn't complementary about the N174 and found Mo Nunn, lets just say, 'very challenging' to work for...
Checking my notes, the Teddy Yip story about wanting to race at Monaco is true. Teddy thought that the answer was to 'talk to Bernie", but Vern said it wasn't that easy. The only F1 car available was the Ensign that Brian Redman drove at Silverstone. Apparently Nunn didn't rate Redman after that drive, and Vern reflected that that 'should have been a warning sign' for him as he had the utmost respect for Redman's ability.
Paul, Tony, (and Vern!) thanks for the information. I'll update the guys over on Autodiva. I wonder if Vern is referring to a test session at Nivelles separate from the Grand Prix weekend, or a testing period the day before official practice. The former presumably, as, at sometime, the 'still green' Ensign was 'Theodored', 'Schuppaned', and painted orange.