[51 MERC-CT]

Same thing happens on my '51 MerOmatic.
Keeping any seal "wet" is not a solution.
The only thing that stops the leak (other than major overhaul) on the floor is to watch the oil level as it rises on the stick.
When the level is 1/2-3/4" above full, start the engine until the oil is pumped back into the converter. (good for several weeks)
The point of leakage (to the floor) is at the shift shaft where it comes out the side of the transmission.
If a suitable seal at the shaft could be installed it would stop the floor leakage but not any converter to pan leakage.