Tim,
Re.the JP paint mystery, the 'bored painters' theory may be a lot closer than one might think !
At Dunsfold, when the last and least 'airfield manager' moved in ( following John Farley is going to be a tough act for anyone, let alone an ex-storesman with no interest in the place apart from wrecking it ASAP for his northern chums ) I accompanied him with a sub-manager on his initial walk-round.
When we got to the paint shop ( where Top Gear were for a while in later times, now they're in half of Experimental ) there was a Morris Marina resplendent in shiny new paint...the newbie flew into a ballistic rage, assuming it was a 'homer' - despite the sub-manager trying to restrain him.
What the sub Brian and I knew, but the idiot hadn't bothered to find out, was that it was a quiet period for the paint shop and it was an airfield vehicle, all totally above board !
Naturally no apology or acknowledgement was forthcoming when the facts finally penetrated the rhino-hide.