I'm guessing the aircon was a special order as the car was destined for hotter climes (Aden or Singapore perhaps)?
One of our number who I haven't seen on here for a while was OC RAF Detachment at Offutt and had a huge Ford station wagon as his staff car (ideal for picking up visiting crews and delivering them to the Ramada Inn!) It didnt have aircon and the RAF wouldnt stump up for a retro fit until he left a meat thermometer in it one day, which recorded 130F. They relented!
Wasn't there something about some retired RAF air marshal being on the board of Standards which is how they got the contract? I dont remember these in service, but the later models in the early 60s which rolling 20 refers to were pretty much hated by MT drivers who breathed a sigh of relief when they were replaced by Mk 2 Zephyrs.