Just now reading about your hull/deck joint, toe rails, and cockpit drains.
Don't know if you're still in the project or finished. Wondering what you came up with. I have a Spencer 42 and am following Hal Roth's idea with his Spencer 35. He glassed the outside of the joint with several layers and eliminated the bolt down toe rail completely. He bolted a toe rail to the stantions. As for the cockpit drain. Spencer's drains are way to small. Hal Roth cut 3 inch holes in the cockpit corners and glassed solid tubes to just above the waterline and exited thru a common thru-hull hole. I'm using a 4" hull hole. I just finished making the exit tube to glass to the hull. It's thicker and heaveir than the hull itself. I haven't make the tubes yet.