Tranny fluid '61 BW

I have a Borg Warner automatic transmission on my '61 MK2 and need fluid for it. What type of automatic tranny fluid should I use?

Ideally FA, which is hard to find except maybe at NAPA. F type has worked for me in the past.

Gerard

A specialist put synthetic trans fluid in my XJ6 (BE12) and it’s really good. It should have FA (Ford) fluid. PO might check if synthetic is good for the DG as well, especially if FA is hard to come by? Paul