Ok, I found the issue. My scene is in meters and the script assumes centimeters. So it was working - it was just moving the vertices 100 times too far. Now I just need to track down how to make the script run Working Unit agnostic.
I'm always amazed when a question I need answered has only been answered just a week or two ago. Especially for a program like Maya which over 20 years old. I'm not a scripter, I have a quick follow up question. So the script gives the pivot position, but then how would I use that position to scale something? Eg. scale 4…