Craig, good points!
Jeeze, I'm wondering now if I should have asked Tim's permission to post this in case someone comes away from it thinking he's not as thorough and meticulous as he is!
My bad. Yes, I did leave some pictures out. I stupidly was trying to "abbreviate" the process.
We used butyl sealant - LOTS of it! He also counter sunk (?) the screw holes in the fiberglass to allow the sealant to ooze into those recesses and also left it over the screw heads when all was said and done.
As for the exposed core, our main concern of the morning was to get the hatch in so I could get at the stern tube to try and apply a temporary patch. He commented on me "properly" sealing the exposed core in the off-season and in the mean time completely slathered the the core areas with yet more butyl sealant. He used an entire tube.
Here he is with a zealous blob around the lip and slathering the exposed core...