Columbia 39 1970 Sanitation and Holding Tank

[pnyby]

Hi everyone, we just purchased a 1970 Columbia 39 sailboat (cutter rig). The original holding tank was taken out, but the original hoses were cut and not labeled, and entirely new hose system was put in for direct-to-sea output. We have to install a holding tank per marina and anchorage regulations, and we're having a bit of trouble figuring out how it was configured originally.

Does anyone have an old Columbia from this era, and have some sort of schematic or diagram of the holding tank hoses and valves and pumps?

We have three 1 1/2" black marine sewage-grade hoses that disappear behind the head bulkhead, and we have only been able to trace one (it goes to the pump-out fitting on deck). The other two are mysterious, though we assume one must have been waste-out into the ocean... possibly.

Any help at all is appreciated!