Three hand-painted London backgrounds from Danger Mouse survive here in extraordinary condition, each one a working piece of the Cosgrove Hall machine that kept Baron Silas Greenback at the centre of British children's television for over a decade.

The Houses of Parliament (bottom left, BG 23/54b) belongs to "Tampering with Time Tickles", in which Greenback deploys green-plus bombs to age London's monuments instantaneously. The Palace of Westminster is rendered at dusk, the Gothic stonework picked out against a warm orange and salmon sky reflected in the Thames below, every buttress and pinnacle committed to by whoever held the brush that day.

The Royal Albert Hall (bottom right, BG 19/86) is from "The Great Bone Idol", with the production annotation calling for a green gel overlay. That gel instruction is still written in the margin in red ink, and what it describes is the eerie glow Cosgrove Hall would lay over this backdrop as Greenback's scheme plays out across central London. The dome, the terracotta frieze, the arched windows, all of it rendered with an architectural specificity that is rather astonishing for a ten-minute children's comedy.

The Tower of London (top, BG 45/6) is from "The Trip to America", the episode in which Greenback shrinks and steals the Tower, selling it to a Texan cowboy named Texas Jack McGraw as a birdie bath. Camera peg holes are intact at the bottom of the sheet, the moat and battlements lushly painted against foliage that frames the composition from either side.

Backgrounds at this level of finish were fleeting on screen, cut away the moment a scene changed. The fact that all three have come through intact, fully annotated, and perfectly preserved makes this a genuinely unusual set. British animation, British landmarks, and one of the best villains the medium has ever produced.