I’m not certain, but the matt black painted Meatbox was probably done so for the 1983 TV series called ‘The Aerodrome’ about a neo-Nazi air force. If I recall correctly if featured T-33s and Vampires painted in fictitious colours, so it would fit in with the ’50s ‘science fiction/futuristic’ timescale.

IMDB says:

Plot Outline: In the future England is ruled by a fascist government, and one day the leaders begin the construction of a heavily guarded, mysterious airport.

More here: http://www.eofftv.com/a/aer/aerodrome_main.htm

SUMMARY
In a sleepy hamlet in the Cotswolds, Roy learns on his 21st birthday that he is not, as he always thought, the son of the village rector*, but that his background is rather more sinister and distressing. And what connection does he have with that strange aerodrome built on the hill overlooking his home town and which is slowly threatening to devour the entire village? Discovering the secret of his illegitimacy, Roy throws in his lot with the brutal Air Force and begins his rise through the ranks of the corrupt and dehumanising organisation. But he soon finds himself stripped of the simple charm he possessed before and only finds redemption in the love of the village girl he turned his back on earlier.

CAPSULE REVIEW
A chilling and powerful drama set in a strange alternate world where mirrorshade wearing stormtroopers strut around the village pub and the local manor house it kitted out with stags horns and neon. It’s a disarming vision of a Britain gripped by fascism that works surprisingly well, given the usual budgetary restrictions of the BBC. The photography is often breathtaking, the ensemble acting is superb and Chapman’s script is both witty and incisive. [Full Review]

*Played by Richard Byars. Now that’s a nasty shock. 😀 At the end of the credits the familiar names of Mike Woodley and Aces High appear.