The B-1A is represented in two versions. The first three prototypes were produced with an F-111 style escape capsule. Download this as B-1A. Two liveries allow selection between the  prototype aircraft with and without the instrumented nose probe.
The fourth prototype was produced with individual ejection seats for the four crew. It had an enlarged orsal spine and tail cone. Download this as the B-1A#4. Two liveries illustrate the white and desert sand comouflage pattern.

The B-1B was developed from the B-1A. It is a much heavier, more capable aircraft though restricted to lower supersonic speeds. It has a longer range and higher payload than the B-1A. Four liveries display the aircraft in grey (Dyess and Ellmsworth) dark grey (Dyess) or “charcoal lizard” (Mountain Home).

The B-1A is armed with SRAM (Short Range Attack Missiles), the B-1A#4 with mix of SRAM plus MK84 2,000 lb iron bombs and the B-1B with GBU-32 JDAM (Joint DIrect Attack Munition).

B-1A was produced in four versions as prototypes.
B-1B is the current operational version.