Hello,
Once you start it is hard to find a place to stop. At the very least, I would replace the front and rear main seals, the filter and pan gasket.
After that all rubber seals, o-rings and gaskets. Once you have gone this far and this deep you will probably not be far from all new clutches being replaced etc, etc. Complete rebuild?
If yours has the riveted torque converter hub, have them pressure check the unit for leaks.