The P-38 Droop Snoot was the brainchild of Col. Cass Hough and Col. Don Ostrander of the 8th Air Force Headquarters. The load-carrying capacity of the P-38 made it a natural for use as a fighter-bomber. The later P-38 variants (P-38H/J/L) had the capacity of carrying up to 4000 pounds of ordinance – the same as a B-17 bomber! Col.s Hough and Ostrander came up with the idea of using some type of a “leader” P-38 for level bombing missions. The advantages of using a fighter in the strategic bomber role were obvious: a much higher speed to and from the target, one tenth as many crew members involved in the mission, and fighter escort during the withdrawal phase was not required. What they proposed was the installation of a Norden bombsight in the modified P-38, one housing a qualified bombardier/navigator in the aircraft’s empty nose gun-bay.

The project, given the code name DROut of Production SNOOT, was formulated at Lockheed’s Langford Lodge modification center in Northern Ireland. A P-38H was modified by removal of the armament section in the nose, including the gun port nose cap. In it’s place, was a solid wood nose cap, cut and shaped like the proposed bombardier nose. With some ballast added, the modified P-38H was flight tested to determine if there were any flaws in it’s flight characteristics. After successfully completing the flight tests, Lockheed modified a new production P-38J to full Droop Snoot prototype specifications.
The wooden nose of the P-38H test aircraft was used to construct a Plexiglas bubble bombardier nose. Armor plate was added to the sidewalls and floor of the bombardier compartment, along with the Norden bombsight, related bombing equipment, oxygen and navigational equipment. During late February of 1944, the P-38J Droop Snoot was rolled out at Langford Lodge.

The concept was so successful that the 8th AF immediately ordered first three, then fifteen Droop Snoot conversions. The total number built lies somewhere between 23 (those P-38J’s converted at Langford Lodge) and 100 (the number of Droop Snoot conversion kits ordered by the AAF). The first combat mission was flown by the 20th Fighter Group on 10 April 1944, when a Droop Snoot led 42 other 20th Fighter Group P-38J’s on an attack against the Luftwaffe base at Gutersloh, Germany. Droop Snoot missions were not confined to just P-38 units. Col. Hub Zemke used a Droop Snoot P-38J to lead his 56th Fighter Group Thunderbolts on at least one bombing mission.
From what I can gather factory birds perspex noses differed from the field kits.
The majority of Marks are from a field kit conversion.("Fubar" being built at Langford) see above