I pulled the pump from the boat. I've posted the photos for your review. http://www.flickr.com/photos/3900645...7606303890014/
1. I'm not sure how the pump attached to the engine - no brackets
2. The impeller was in good condition with all vanes okay
3. The cover of the impeller housing showed signs of inconsistent wear
4. There was metal debris from the rings and the bearings were off the pump
5. I don't think the mechanic pulled the cover due to two reasons: 1) he would have seen the wear on the cover and 2) the crap in the storage bins was not moved. Given the location of the pump there's no way he could have accessed it without disturbing my junk.
The plot continues to thicken as the photos make it seem like the problem was diagnosable.