Can I have multiple/alternate UV textures for one mesh in a single file?

I have a mesh that may have multiple instances on screen at the same time in a game. However, each instance may have a different "skin" to give some variations. Like coins that all looks the same but may have different denominations on the faces. Even the edge ridges will have the same texture.

Is it possible to combine all the possible different UV Textures into one file and reference any of them in the script at run time?

Now, I'm thinking this would reduce draw calls and resource consumption since I would be loading only one texture file instead of 20 -- as is in my case. True?

One mesh, multiple alternate textures, 1 texture file.

Is it possible?

Thanks, Manny