Mercury 40HP 2-stroke oil leak - not the reservoir

[RFHVA]

I've searched the forum and can find the answer. This is my first post here so be easy on me if I missed it. This is not the tilting of a cracked reservoir issue I?ve found all over the internet. I have a 1999 Mercury 40HP 2-stroke (SN: 0g772101) that has a slow, constant 2-stroke oil leak. I am restoring the house houseboat it is on, and it has not been run or in the water for two years. Last fall I rebuilt the carbs, inspected the impeller, and changed the gear lube. I called it ?done? and filled the 2-stroke reservoir with fresh oil, but have yet to add any gasoline. ALL winter it dripped in my driveway (while level and not tilted) until it was empty. This was going on before I got it. It seems to be coming from an internal engine leak because it runs out from the seam just below the powerhead. I degreased and dried it completely to try to find the leak. I used q-tips to check all oil lines and seams but don?t really find any hard evidence like I think I should see (no blue oil on them). I popped the lower carb drain screw and found nothing. I?ve pulled the lower spark plug and found nothing. The oil pump to engine seam concerned me so I replaced both o-rings in the oil pump that seal it to the motor last week. I thought that would have fixed it so I filled it up again. It still has the same thing going on. There is no residue that I can find anywhere on the oil delivery system. It?s dripped out about a ?? of oil from the reservoir already (6oz or more?). Is there an internal seal or o-ring I?m missing? I have the manual for the engine. Give me a part number for any suspects so I can look at the diagram.
Thanks! Frank