Type A transmission fluid is still around, just not necessarily in the "name brands" any more. Grocery stores, auto supplies, and other places might have some on the shelves. Starting in 1968, Chrysler and GM went from Type A to the Dexron family of fluids, which should be better fluids with better additive packages and all of that stuff. The current Dexron is Dexron III.
In some respects, finding some Type A fluid could well be worth the effort to find it. In other respects, the newer Dexron III fluid (that GM states is backward compatible with all of their transmissions to 1947) would be an option. If the power steering system you have has not been resealed since the Dexron years, finding some Type A fluid might be a good idea.