Had some water damage in my kitchen from upstairs bathroom, selling house in the next couple months and decided to take down the ceiling tiles. Tiles covered really bad lath and plaster, pulled that down and looking at galvanized supply and waste lines to tub and toilet. How far do I go.....the old question......replace waste all back to stack.....remove supplies and put in PEX?.....Or just sheetrock over it and wish the new home owners best of luck?