Son of a bitch. I read this post over the weekend and didn't think much of it. When I pulled my boat out of the water and looked everything over, I noticed a good film of oil in the bilge. I thought it was always coming from the oil filter adapter. But after reading this post, I decided to check the inside of the rear motor mount, where it covers the fly wheel. Sure enough there was plenty of oil built up in there. I'm not going to worry too much about it right now, but I will be keeping an eye on it.
Oh yeah, it should be a 2 piece seal. It compresses pretty well when you put the cap back on. If was one piece, well you know the routine.