It's too large a difference. 1.0mm vs 1.07mm and 1.1mm.
Further more. 1.07mm and 1.1mm were taken with the same Digital Caliper, so there's 0.03mm difference between the keys on 1 keyboard (Red) and the keys on another keyboard (Brown).
Like you said "Damn those German Cherry Corp engineers are good.". All the Red switches were consistently 1.07mm and all the Brown switches were consistently 1.1mm
Do you have a Cherry Corp datasheet stating the width of the vertical stem?
My red switch does not look like the red switch in your picture.
My red switch looks like this minus the diode.

One thing I've noticed is the Vertical Stem part is not a sharp 90deg angle like in the datasheet but a tapered edge.
My Red switch is similar to

as opposed to

Lets wait for more people to respond with measurements.