I have not changed the filter nor fluid myself, but it should have been done less then 900 miles ago. The fluid looks clean and fresh. There is only not an F type fluid in the transmission, its not available overhere. The fluid which is in there is a Dexron III equivalent. It shifts fine, the only problem is Reverse when hot.
1958 T-Bird "Trovão Rosa" - "Rose Thunder"
Thunderbird registry #61670