I have two baths in my house with the fiberglass tub/shower combined. The faucets in both need to be replaced as the seats are at the end of their life and leaks (drips)are present. My problem is there is no room to access the mixing valves in the bathroom itself without removing one of the units, its on an outside wall and the other could be accessed by cutting into the adjoining room wall. The unit that is on the outside wall has only about 3.5" space to work. I really dont want to have to replace the units at this time. Any suggestions?