Found some more info on markings. The way the tail is stripped is a marking used for joining up in large groups. An excerpt from WE WENT TO WAR.
Part V: Tail Markings
380th BG History -- Part V: Tail Markings
Like most combat groups before Fall 1943, the 380th went into combat with the aircraft painted the standard OD on the upper parts and sides of the aircraft and the standard neutral gray undersurfaces. This was modified only by the national insignia and, in many cases, a name with nose art. As in all theatres, a problem soon arises when planes needed to formate or rendezvous prior to hitting the target. If more than one group was involved, it became very difficult to tell the different units apart and some form of highly visible identification became necessary. The presence of the large twin tails on the B-24 made them the logical place to put whatever identification symbols were employed. This situation became critical in the Southwest Pacific area when MacArthur began preparations for the Cape Gloucester invasion of New Britain Island in late November 1943. all available bomber aircraft were scheduled to take part with three B-24 groups involved. An order was therefore issued for each group to pick a distinctive marking.
The 380th chose to paint the fins and rudders of their planes in a scheme of quadrants, as shown below. These pictures, for clarity, show the scheme after Spring 1944 (Northern Hemisphere seasons) when the OD paint was removed from our aircraft. The first version was to paint the chosen quadrant white on the
OD background. As noted, this was changed to black on NMF (natural metal finish) the following April-June period.
(The 380th had the lower right quadrant of the tail painted black.) So it appears the black was stripped off for the contrast with the bare metal finish.
I also found they were lost on the return from the 38th mission for this aircraft, to Macasaar with an observer on board, Maj. LATREILLE, Henry Robert, Aust Army VX21828.
Am fitting the fusey halves together, gotta put some weight up front tho. Masking the turrets is a right royal b!tch. Painting the inside of the engine cowlings. Gotten some scale props and have painted them and the hubs, now for their decals. Slowly but surely.