In the interests of thread necromancy......
Today I took the
hacksaw and gave the rear rim of my retired Ksyrium maximum elbow. It didn't take long.
According to Mitutoyo, the braking surface at its thinnest point (just above the web, on the left of the pic) is 0.72mm
At its thickest (just above the bead retaining ridge on the left of the pic) is 1.32mm.
I'm comfy with the notion of having replaced the wheels when I did.
Interesting things Jurek found when dismantling the wheel:
The nipples (which cannot be separated from the spokes) have (what measures up as) an M7 thread, with a really steep pitch and (there's more) a LH thread. So - looking from the hub outwards towards the rim, you'll be turning the nipples, somewhat counter intuitively, clockwise to loosen spoke tension. The nipples screw directly into holes threaded into the rim rather than onto the spokes.
The rim was full of dry, crystalline, powdery stuff which I took to be dried up thread locker.