I work at a parts store, maybe I could help you. That Shell ATF is probably a "Multi-vehicle" ATF. and will work just fine in the AW-4. I know i sell quaker state and castrol multi's that work in transmissions that require Dexron and Mercon III. The V and VI are meant for alot of newer vehicles, and you don't want that in your AW-4.
Trans fluid is usually expensive, except for lower brands like the Walmart Tech-2000 stuff. Just make sure you get the right one!