For some reason today's date has some sort of meaning, who knows

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Here's a nice bit of reading for those interested with additional photos.
http://timothyblotz.com/2012/04/13/the- ... old-story/
"Two of Doolittle’s B-25′s awaiting the installation of extra fuel tanks at the Mid-Continent Airlines hangar in January 1942. This is a critical photo for two reasons. First, the tail number of the right aircraft matches the manifest of Doolittle’s after action report on the raid on Tokyo. Second, the aircraft is clearly guarded by two armed sentries which speaks to the secrecy and security concerns of the fuel tank modifications." (Courtesy: Tom Norrbohm)

"B-25 #2242 at Wold-Chamberlin Field. This B-25 was flown by Capt. Ed York and was the 8th plane to launch from the deck of the USS Hornet and the only plane to survive the raid on Tokyo. Capt. York safely landed this aircraft a Russian airfield about 40 miles north of Vladivostok." (Courtesy: Tom Norrbohm)

"One of Doolittle’s B-25B Bombers at the Mid-Continent Airlines Hangar in Minneapolis during the winter of 1942." (Courtesy: NWA History Centre)

"One of Doolittle’s B-25′s at Wold-Chamberlin Field in Minneapolis. This picture is significant for two reasons. First, it is taken inside the security zone, perhaps by a contractor. Second, is the presence of an armed sentry. The sentry provides importance to the secrecy of the modifications being conducted on the B-25′s." (Courtesy: Tom Norrbohm)

"Another view of the one of Doolittle’s B-25′s at the Mid-Continent Airlines Hangar in Minneapolis – 1942" (Courtesy: NWA History Centre)

"B-25′s at Mid-Continent Airlines Hangar in Minneapolis." (Courtesy: NWA History Centre)

"B-25′s of the 17th Bombardment Group at the Mid-Continent Airlines hangar in Minneapolis as they were being retrofitted with extra fuel tanks for the raid on Tokyo. The picture is signed by four crew members of the mission. These signatures were most likely obtained well after the Doolittle raid by evidence of the fact that David Davenport signed his rank as Colonel. Davenport would have been a lieutenant during the mission." (Picture Courtesy: NWA History Centre)