The designation "XB-26E" was unofficially applied to a weight-reduced version of the B-26B/C that was produced by the Martin-Omaha Modification Center in January of 1943. B-26C-5-MO 41-34680 was selected for the tests.
Somewhat whimsically, the stripped-down aircraft was named Gypsy Rose, after the well-known stripper of the day, Gypsy Rose Lee. The gross weight was reduced by some 2600 pounds by deleting certain things such as provisions for AFCE, the SCR-287 liaison radio set, the navigator's seat, oxygen equipment, the toilet, astrocompass, astrodome, astro-graph, outlets for electrically-heated clothing, the K-38 camera mount, plus the rear bomb bay racks.
As part of the program, the dorsal turret was moved forward and mounted over the radio operator's compartment. This resulted in an improved field of fire, and the relocation actually improved the flight characteristics. The plane was tested at Wright Field in March of 1943. Maqny of the weight reductions tested ended up being applied to the "single-pilot" B-26C-5-MO.
In 1943, the USAAF authorized Martin to build a couple of experimental Marauder versions. One was a ground attack version that would operate as a strafer, whereas the other was to be a bomber version with revised armament. Both were unofficially known as "B-26E".
The strafer version was to have featured heavier forward-firing armament. B-26B-40-MA 42-43319 was experimentally fitted with a revised nose containing a fixed forward firing armament consisting of two 37-mm cannon and two 0.50-inch machine guns. Side windows were added just behind the nose, and more armor was added for crew protection. A twin-tube rocket launcher was mounted underneath the fuselage. The system was tested successfully, but was not adopted for production.
The bomber version was produced by modifying another B-26B. It had the upper turret moved forward on the fuselage to a position formerly occupied by the navigator's compartment. This permitted the waist gun hatches to be raised upward and moved forward, giving a better field of fire. A weight reduction program was to have reduced the loaded weight by 2000 pounds. However, this version was never built.