My 1983 46 SS has the holding tank under the forward center island berth. Don't know if its original to the boat.
Ummmm. Does it have a deck fitting labeled holding tank? If so, the tank should be in close proximity to it. A 1984 boat should have a holding tank.
Yes it has the fitting for evac but owner told me it went over the side...new to me boat and wasn't ready to crawl around behind the motors etc yet
On my OY 44, 1987, the holding tank is in the companion way under the floor board between the main stringers.