One can distinguish between the Volvo and Saturn by the S2 solenoid. The SLS and SLT solenoid will identify between the first and second design. Another, possibly easier, way to identify between the 1st and 2nd design is by locating the casting letter located just above and to the right of the SLS solenoid. No letter or an "A" will indicate 1st design and the letter "B" or "C" indicates 2nd design.
For GM and Saturn the AW 55-50SN might also be referred to as the AF33-5, and for Nissan it is referred to as the RE5F22A.
When replacing the valve body and or rebuilding this transmission a reflash or relearn may be required for proper performance. In some models shift feels and downshift clunks could result as well as shorter transmission life. Always use proper transmission fluid.