"Once the floor is in place and interior bolts installed, the shell will be lowered into place and secured to the frame at the outriggers and to the floor only with screws elsewhere."
I assume that you will bolt the floor to the frame using elevator bolts and that this is what you mean by "interior bolts".
One of the best visuals I've found on construction is post #20 of this thread:
On my '65, I found that the c-channel was trash and had to make up a new one. I would definitely inspect it well, replace if necessary and buck rivet the shell to that c-channel and NOT use screws to connect the shell to the frame. It's a critical part of the monocoque construction.
On Epoxy, you're not confusing West Marine with West Systems Epoxy, are you? They are totally separate companies. West Marine is not the only place to get West Systems Epoxy. Head east to a good boat store if you want to find it, you're not far from the water.
The previous thread I mentioned and this are great resources:
Be careful, you're on a critical part of your project. Research it well!