So, here is a photo of the spot under the way wipes. I guess now that I'm looking at it its not as bad as I was thinking, going from memory.
Here I set the camera angle and lighting to be as visible as possible. The backside of the way looks pretty much identical.
The wear is practically zero at the bottom of the way face, and zero at the top, but about .0005" deep in the middle. It tapers gradually to none at the tailstock end.
I determined this using a Tesa .0001" test indicator in a magnetic base, attached to a 123 block, with a hss tool black clamped to the 123 block. I kept the clamped-on hss blank indexed against the ground backside of each flat way while sliding the 123 block down the ways and measuring.
I measured both faces of that v way, several times each at various levels.
The various measurement passes taken from the flat ways agreed with each other very closely, so I'm reasonably confident in the readings.
All of this wear occurred years ago, before I scraped the saddle. Back then, my precision (.0005" per foot) level showed the bubble move about 1-1/2 full graduation while transiting the worn area. The saddle was only contacting the way in a small area near the center of the way faces.
After I scraping in the the saddle, I can run the carriage all the way from the headstock end to the tailstock end without the bubble moving. I believe that after scraping the saddle to a good 30ppi contact pattern, it's now pretty much straddling the narrow wear area.