Brewer 44 Forward Holding Tank

Hello Brewer friends. My forward holding tank is located under the v berth on the starboard side. It is purpose built right into the structure of the v berth (NOT a separate tank that fits into the space). The previous owner did not use the forward head/holding tank for whatever reason. In fact all the plumbing lines were hacked and the lid/top of the tank removed.

Does anyone out there have the same setup? Photos would be very helpful, as I will need to fabricate a new top/lid.

Thanks, Matt Davis
s/v YOLO
1990 Brewer 44

Please find the attached pictures. Any suggestions on how I should proceed with this as a holding tank?