Tom, I think the vs1 announces the version number, let me know if and how.
Power off the radio, remove the top cover, and near the right hand bottom 
corner of the open area, you will find a small slide switch.  I think it's 
in the bottom half inch corner on the right side.
I can't remember if the instructions came from this list, or were a part of 
the firmware upgrade upgrade.  I heard it somewhere, but it's been years.