Except for a layer of dust, the insides look pretty new.
While I have it apart, one area I've wanted to take a closer look at is the flow meter.
Here's picture of the assembled flow meter:
This is a picture of the meter with the magnetic pickup removed. (You need to loosen a hex screw on the front of the meter to remove it. This is best left until AFTER you remove the 3 hex head cap screws that hold the black reinforced plastic cover onto the brass manifold on the bottom).
Here it is with the top cover off. Do this, you'll need to get a sharp chisel between the cover and the brass manifold to wedge it up and out (there is a tight o-ring seal inside to prevent leakage). Once open, you can see the small, white telfon vaned rotor that spins around. On top of the rotor are 2 metal inserts that spin past the magentic pickup above and produce the signal. Two metal passes correspond to one rotation and a fix volume of water. The white circle around it is a o-ring seal.
If you look closely in this photo and the next, you can see the hole in the manifold on the right where the water enters (just below the water line) and on the left is the exit hole.
In this shot the teflon rotor has been removed. You can see that the pin where the little rotor sits almost frictionless. Didn't seem worn, but if the rotor did ever wear out, it would be nice if you could replace the little $5 rotor (but I've hear you need to buy the WHOLE thing).
In this last shot, you can see the tiny rotor with my thumb next to it for perspective. The vanes are square, but I've seen some that have melted where they can appear almost rounded.