Well, I have a book written by C. Ross Greening, the man who created the "Mark Twain" bombsight used in that raid. I may be able to give you some info from it. The "Mark Twain" shouldn't be too hard to replicate. Also, it says that they removed the tail guns and replaced them with black broomsticks, and the broomsticks were bigger in diameter than the .50 cal. brownings. I was thinking maybe replace the two .50s in the tail with 2 20mm cannons, minus the ammo. The broomsticks could still train enemy planes. It might also be possible to make a skin for every plane that flew on this mission. On another note, the "Mark Twain" was later attached to the Norden's mount, so the bombsight tracking could work (though the bombadiere still had to release the bombs). If you would like to get a copy of the book, it is called Not As Briefed . It is in paperback, and contains his entire account of pre-war training, the Dolittle Raid, North Africa, Italy, being shot down over Vesuvius, POW in Italy, escape and hiding, recapture, POW in Germany, the escape plots of POWs, his arts and crafts, and finally liberation by the Russians and return home. He was at Stalag 1, with Hub Zemke and one of the guards was Max Schmelling.
I recall reading from that book that over Japan he and his crew encountered a rather German looking fighter, and it was the first American encounter with a Ki-61. His plane was nicknamed "The Hari-Karier".
Greening's account of the "Mark Twain":
"According to the plan we envisioned, we needed to bomb targets from an extremely low altitud. Our planes, however, were equipped with the Norden bombsight, which was designed to operate efficiently at 4000 feet or higher. The Norden could be used at lower altitudes, but not with its automatic features. Furthermore, it lost its effectiveness below 4000 feet during the extreme maneuvering of a short bomb run. It was expensive too, costing over $10,000 each, and was highly classified. We didn't want to risk having it fall into Japanse hands.
As a result, I decided that we needed a substitute. As the mission's armament officer, I set about designing a new bombsight specifically for this mission, one that could be effective at altitudes of 100 to 1,500 feet. Sgt. Edwin Bain, my assistant technician, and I gave this problem a lot of thought. We obtained scrap Dural aluminum. First we made drawings and then at the shop cut a 7" x 7" quadrangle to install on the Norden mount. We inscribe a 90-degree arc facing forward with markings 10 degrees apart. On this quadrangle we fixed a vertical 5 1/4" x 7 1/4" piece of aluminum. This had a rounded top and it pivoted horizontally on the quadrangle plate. There needed to be a pointer to work with so that a relative directional bearing could be obtained. Thus, in the upper rear quadrant of the upright piece, we marked off another 90-degree arc so we could get an up-and-down slant angle. The attached sighting bar on this vertical plate was a piece of right angle aluminum with a simple V notch for the rear sight, and a pointed front sight that would fill the V just like a rifle sight-a crude one.
Sgt. Bain and I thought it would work, but because it was so simple we couldn't be sure. All the bombadier had to do was pivot the horizontal plane and tell the pilot on the intercom how many degrees right or left to steer to line up on the target. The gun sight, of course, was aimed from the bombadier's window at the front of the plane.
Later, we made improvments by connecting the gunsight to the remaining linkages that served the Norden sight. This permitted a bombadier to give course directions to a pilot through the PDI (Pilot Direction Indicator) instrument without relying on voice communication. The turning of the sight either left or right by means of a handle would deflect the PDI needle to the right or left, directing the pilot to follow the perscribed heading. With a B-25 on an attack course, all the bombadier needed to know was the plane's speed and altitude to set the verticle angle of the gun sight. When the target came into his lined-up bead, the bombadier prepared to "pickle off" his bombs.
All a bombadier did next was set a dropping angle taken from a sieries of tables fastened to the Norden bombsight base. It was a double drift attachment hooked onto the base, which permitted us to determine proper dropping angles for any sized bomb, at any altitude, in any wind conditions, and at any ground speed. This was all computed automatically once the wind speed was known. A bombadier only needed to set the dropping angle on the verticle plate, then aim the bombsight in the direction of the target just like he would a gun. As the airplane flew to the target, of course, he would have to raise the tail of the sight to keep it on the target. As it contacted the stop or dropping angle on the vertical plate, the bombadier released a bomb, generally with good results."
It was later calculated that the materials for these sights cost a total of 20 cents.
