LB, similar, nice new STEEL boards in Bomber Ops at Akrotiri, captains' names and sundry other gems carefully printed on to acetate strips, two magnets glued to strips and Bob's yr uncle. Just a moment to update board or rearrange the strips.
As luck would have, all was ready when the Taceval team arrived. Entered the bombproof tar paper shack, passed through the outer door, through the inner air lock (to keep cold air in) and saw the super new and pristine display boards.
The inner door was spring loaded shut. As it slammed EVERY strip fell off the wall. Display 100%, resilience 0%.