Cool Project! Looking forward to hearing about the gel coat. Funny how a small job turns into a full-on resto. I was going to go with black on the bottom as well... I guess engineers all think alike. In the spirit of not cramping your style, I'll do something else.
Couple of questions:
What made you decide to go with US Composites instead of GelCote Intl?
What did you come up with to get the exhaust thru-hull fitting out? I was thinking about sacrificing one of my cheap Irwin woodworking clamps - it would need to be cut to get it in there, but I'm not sure it would work. Might be best to fabricate a tool.