Changing the 3 speed auto fluid anything I should look for.

I have a '66 300 with a 3 speed auto. It has sat for 30 years and I am changing all the fluids among other things. The transmission fluid is leaking from the pan. I know there is an interior filter is there anything else I should look at while I have the pan off. There where no issues previously with the 62,0000 mile transmission.
Author: Zymurgy