There are several possible leak points on the Fordomatic.
1) The front pump gasket and seal (which you have indicated was done)
2) The large O-ring seal between the cover and the converter housing.
3) The lip seal and o-ring seal on the transmission shift lever and throttle valve lever on the side of the transmission case. If you pull the transmission to do the converter o-ring, you should do the side lever seals also because it is much more difficult to do with the transmission in the car (can be done, but much more difficult)
4) The rear shaft seal (but you can usually tell if this one is leaking and it is easy to do in the car.
I bought parts for the project from
www.autotran.us and you will have to call in the order but it is one of the best sites for old Ford trans parts.
Here are a couple of videos that are helpful. The first one is a complete rebuild and quite long, but if you forward to the 2:00:00 time frame it details the converter o-ring seal installation.
https://www.youtube.com/watch?v=JwenorNpQtY&t=7332s
This next video shows the shift lever/trans valve lever seal replacement (done in the car but you can use this for how to do it with the transmission on the bench also).
https://www.youtube.com/watch?v=9MGTw76w5YE
Good luck,
Dave