They drew cartoons, graffiti, murals, glamor "pinups," combat scenes, mission records and maps. U.S. servicemen at bomber and fighter bases in central and eastern England between 1942 and 1945 created a huge but largely unrecorded body of wartime artwork, some of which has survived more than 70 years in collapsing and overlooked buildings.

As the 70th anniversary of D-Day approaches, a "last chance" search is under way to find and record the scattered vestiges and fading memories of the largest air armada ever assembled — before decay, demolition and redevelopment remove the final traces.

New research might also offer clues to the fate of the "Sistine Chapel" of wartime air base artwork in Britain — a large mural by the celebrated British cartoonist Bruce Bairnsfather, painted at a U.S. base in Northamptonshire in 1944. The 30-meter mural, in part depicting a ship bringing GIs back to New York, has not been seen since the 1950s.