No Image Lot 297 'DANGER BUTTERFLY BOMBS LIE HIDDEN HERE' WWII WARNING SIGN. 297'DANGER BUTTERFLY BOMBS LIE HIDDEN HERE' WWII WARNING SIGN. Bishop & Miller Auctioneers Ltd The World War Two enamel warning sign measuring 46cm x 30.5cm. N.B. some of the first butterfly bombs were dropped by the Germans on England in WW... Add to watchlist Live