I do have an Advantage (at work) and a KB120 (in storage). Some day I may get around to measuring them as well.
Earlier in this thread, I scratched out a diagram showing the two rows key types I assigned the designations"G" and "H"....(I know, it's crude, but I did it quick to get info to our new GH buddy Razor1987). This was using key caps from either a 130 or 132 Essential.
Some key cap info:
Doubleshot keys on Model 100 (black legend), 110, 120. Singleshot keys 130, 132 Essential, 133 Classic, 134 Professional, Advantage, Advantage Pro.
Doubleshot keys have a shorter "skirt" or the "sides of the key cap" than the singleshots.
The doubleshot keys that have dual legends...only one of the two legends is doubleshot.
I have a 134 Professional with dual legends (qwerty/dvorak) that is doubleshot. I suppose they were just 'using up' their dual legend stock so it happened to be a doubleshot set.
On my Advantage SN# 82000, the key caps (your rows P5 and P6) are the same exact key cap in size. Same key caps, no difference.On my 134 Professional with doubleshots/dual legends (your rows P5 and P6) are the same exact key cap in size. Same key caps, no difference.
Either on my 130 or 132 (your rows P5 and P6) are different as you show. ------I will go and make other comparisons in the next day or so and update this line----(I have 5 models to compare)
If anyone has any questions, please ask now, not later. Taking all these key caps off all these boards to measure and compare is a chore
EDIT---With this info/diagrams that kps provided (Post #46), it should be possible to look for replacement key caps.