Type A ATF fluid, where to find
If you have a Mercedes Benz dealer in your area, you can find Type A ATF there, as old Mercedes passenger cars transmissions use Type A fluid only. Part number is #A 000 989 26 03, and you will probably end up with a Shell Donax TM Type A one liter bottle. NB: Very expensive by the way.
The next closest thing to Type A ATF fluid is Universal Tractor Fluid (UTF), designed for wet brakes applications on farm tractors. Many old tractors recommended Type A fluid and it cross-references to UTF. You can find UTF at Wall Mart (Supertech 2000 Tractor Fluid) and many farm supply stores. Mobil 424 is also a good brand of UTF. I have used it in my A55 and works fine, and dont forget to put a John Deere bumper sticker on your Tomos!!! :=)