Hi
I looked in the paperwork I got with my '73 from the previous owner
and there was a choice of a self-contained recirculating head
(4 gal.) or the flush thru head (where permitted by law) The holding
tank was optional and was 20 gal. I looked at the layout drawing and it just shows stowage under the v-berth. I did not see any other
reference to the location of a holding tank but I think it would have been under the v-berth. Then the question is how to get a tank under there. I had the flush thru tank when I got the boat 20 years ago and it had a small plastic bag under the sink in the head to make things look legal for the coast guard here in Maryland. I changed to a porta- pot.
Dan