On Sat, 08 Apr 2006 21:42:21 GMT, Gary wrote:

All of this
is unneccesary. Mine worked fine, (and so have yours) for almost 40
years. Gary Mull was a good designer.

I agree. Install good quality ball valves on top of the existing thru
hulls, use reinforced hose rated for underwater service, and call it a
day. I had virtually the same configuration on my old Cal-34. We
replaced the original gate valves with ball valves at the request of
my insurance company and everything has been fine for 20 years since.