The missing clad will show two things. The red color and a weakening of the devices:

But your coin has neither. It was a normal coin and spent sometime homeless and was found by a metal detector.

If you want to experiment with it. Carry it with your change and take images once a week and watch the silver color come back to your coin. It will start off brown showing some gray color on the tops of the devices. Then the brown will turn dark from circulation and start looking more antiqued:

The last area to turn back to gray is the fields.