Ross, these are excellent pictures. I have a boat almost exactly like yours. I wish I had found your pics two years ago when I started refurbishing my boat. You are correct in all your labeling. As to the shower drain pump switch that is located near the toilet and sink in my boat and should be turned on when the shower is in use. I have replaced many components including the freshwater pump, the refrigerator and the elements to the water heater. My macerator pump is shot as he is my shower drain pump. I plan to replace the shower drain pump but I may not replace the macerator pump sense, generally speaking, it is illegal to pump human waste overboard.