New Holding Tank seems to work fine...q
I meant to follow up on this thread sooner, but I guess I've been trying to sail a bit!
I did install a Ronco plastic holding tank (B-238, I think) in the locker just forward of the port forward bulkhead on my 1971 E32. It took a little elbow grease, opening up the existing hatch opening a bit, and a few 45 deg. and one 90 deg. elbows, and some new hose. Suggestions in a couple of threads on this site were very helpful.
Bottom line, it is a 14 gallon tank, narrower at the bottom, expanding at the top to match the hull shape. Y-valve to shift from overboard to tank and back. It has worked flawlessly so far, pumped out a few times. Raritan PH2 head. I have plumbed it so that a flush uses fresh water from the sink when sending to the tank. Overboard uses raw (salt) water by throwing the raw water intake valve to open.
If anyone is thinking of doing same, email me and I can provide more detail. I built a couple of "model" tanks to figure out how to maximize the space, and how large an opening I needed to create.
Happy so far!
John B.