727 Pump/TQ Hub Seal Leak

A sleeve that only covers the converter in the seal area would work. But there's probably a seal that would fit tighter.
I aske Dynamic, they use a Federal Mogul but didn’t know the part number and I haven’t found that brand of pump seal anywhere. I thought about a sleeve but don’t know how to determine the size I need. They are an extremely tight, pressed fit so I am a little lost as to proper diameter.