Hi, i am about to remove and replace my very old bath , i have done as much research as i can on what i will need etc, i have taken the panels of to have a look at the pipework and i have noticed that the overflow is going straight outside via the wall , the pipe looks like it could be lead. The waste is a plastic and looks pretty new . What i would like to know is would it be ok to purchase a combined waste and overflow and get rid of the origanal overflow pipe. Thanks