This post on that thread by Camaraderie sounds like it's exactly the same system I have, except the length of hose between the thru hull and the chest. Since mine is factory and it sounds like his was as well, I wouldn't be surprised if it's exactly the same system.
"Well...my Tayana 52 had a sea chest and it is a wonderful idea.
The large through hull connected to a sea cock and a 1.5" hose which then fed a stainless steel
cylinder with 6 valved connections off of it. Inside the cylinder was a strainer basket so all water
reaching the outlets was clean of debris. The top of the cylinder was a flange with 8 holes in it and fitten on top of that was a rubber gasket
AND a drilled plexiglass cover. This was all snugged down by 8 bolts with wing nuts.
The sea chest fed engine
, 2 a/c's, and a wash down pump with one spare outlet.
The best thing was that I could look down on the chest and SEE the water
flowing and the large strainer was easy to get out and clean and lasted a lot longer than the small in line strainers would otherwise have been. An added bennefit was only one through hull to secure and an easy way to winterize...just keep filling the chest with the pink stuff while the through hull was closed!
We DID have problems with the stainless body corroding at the welds. This was cured by an epoxy interior
coating. If making one from scratch today I would be inclined to fabricate it out of fiberglass
Hope this is helpful. "
Cam - I am no longer a member here. Look for me on other forums...same name.