Chief, what jerry said. Hopefully the boat itself doesn't have any left either, but that was standard practice in C-30's back in the day. If there are any left, they need to come out on the next haul out. dbschulz and I are talking about that offline now. It was a few days work..probably one weekend if you went at it full on. I suggest backing plates 5200'd to the hull & marelon seacocks & thru-hulls fittings
How'd the bypass for the engine get built with a gate valve??