Shower Plumbing Shower Water Supply Plumbing?

Shower Water Supply Plumbing? - shower plumbing

Should I pipe my old mother bathing water. It has a tub / shower, and I have to replace a part, as
The hot / cold water faucets
The nozzle that fills the tub itself
The few changes to / from bath / shower
That is all one unit, the metal pipe is old, and no compromises closure. Note that the plumbing was old, and I want to go ahead and replace it with a plastic pipe

Seeking to follow a simple pattern, it should look like the plumbing.